By In Stuff

The Run Differential Breakdown

*Re: above graphic — I suppose this was in 2016. Unsurprisingly the Cubs did not quite hit that 579 run differential pace (no idea when in the season this graphic ran). They finished the year with an excellent but not all-time record 252 run differential.

When it comes to advanced stats, we often talk about wins — wins above replacement, wins above average, win shares. Let’s try something else here and go even more basic. Let’s break down runs … and more specifically, run differential.

To do that we have to start with the obvious: Every baseball game has a winner and a loser, and because of that there is a run differential. In one game, it really doesn’t matter if you win by one or 10 runs, it all counts the same. It’s all equal to one win.

Because of this, there was long a feeling that only a subtle connection existed between run differential and won-loss record. After all if you beat a team by 10 runs, and then lose the next 10 games by one run, you have a 0 run differential but your record is 1-10.

Thing is, over the long 162-game season, there turns out to be a strong correlation between run differential and won-loss record. Bill James was perhaps the first to see it; he came up with his now famous Pythagorean Theorem of Baseball which says:

Runs scored ^2 / runs scored ^2 + runs allowed ^2 = estimated team’s winning percentage.

Take the Red Sox last year. They scored 785 runs (squared that is 616,225) They allowed 668 runs (446,224). So the formula:

616,225 / 1,06,449 = .580.

The Red Sox actual winning percentage was .574. Pretty close.

In later years, people have figured out some math tricks to improve the Pythagorean Theorem and get the numbers even closer. But the point is that while everyone tends to look at wins and losses — especially when predicting an upcoming season — let’s try something else. Let’s try looking instead at runs scored and runs allowed.

Here’s why: To be a solid playoff team, it is helpful to score 100 more runs than your opponent over a full season. Last year, eight teams outscored their opponents by 100 runs. All eight made the playoffs. The last 32 teams, going back five seasons, that scored 100 more runs than their opponents have made the playoffs. The last team to fail to make the playoffs: The 2012 Tampa Bay Rays. And, heck, they won 90 games.

So let’s begin with this premise: Real playoff contenders are teams that can outscore opponents by 100 runs. How do you do that? Well, that’s the fun part: To do it you have to be 100 runs better than league average. If you score 50 more runs than league average and allow 50 fewer runs than league average, voila, you will have a 100 run differential. Cool right?

Well, I think it’s cool.

Thing is, you don’t have to split it evenly; teams rarely do. If you have a ridiculous offense that scores 200 more runs than league average, you can have a terrible pitching staff that allows 100 more runs and you still hit the number. And the opposite is true. Breaking it down this way, I think, allows us to look at teams a little bit more directly. It’s something to look at, say, the Seattle Mariners and think they need to win 12 more games to be a real contender. It’s another to look at their minus-22 run differential and think: How are they going to find 122 more runs? Will they improve their pretty good offense or their really subpar pitching? Or both?

So let’s do that, team by team. For each team, we will list how many runs above/below average they are on offense, same for pitching/defense and then we’ll list off the run differential. I guess I should say up front that for pitching/defense, in order to make it consistent, the Yankees being 103 (Runs Above Average) actually means they allowed 100 fewer runs than league average. Above average is good. Below average is not good.

Let’s make this even more wonky: I’ve added a “Ballpark effect” line. This is because for some teams with extreme ballparks, the runs above average can be deceiving. For instance, Colorado scored 81 runs more than average, which is a lot, and the Rockies gave up 14 runs less than average … but it was actually their PITCHING that was well above average. To show this, I teamed up with resident genius Tom Tango. He showed me how to do this using Fangraphs excellent RE24 — basically run expectancy — which takes ballparks into account. If there’s a large difference between actual runs and RE24, I’ll mention it. If the ballpark effect isn’t too much — this is true for most teams — I’ll just say, “Negligible.”

OK, let’s do this:

American League East

  1. Yankees (Offense: 95 RAA. Pitching/Defense: 103 RAA. Run Differential: 198 runs).

Ballpark effect: Negligible.

You like to see is a balanced run differential — the Yankees are one of the most balanced teams in all of baseball. Last year, their offense and pitching contributed almost equally to the team’s success. You would expect the offense to score more runs this year with the acquisition of Giancarlo Stanton, but don’t sleep on the Yankees pitching. The rotation is somewhat iffy but that bullpen is flat-out ridiculous.

  1. Boston  (Offense 22 RAA. Pitching/Defense: 95 RAA. Run Differential: 117 runs).

Ballpark factor: RE24 shows Red Sox offense 13 runs BELOW average and the pitching 139 runs above.

As you can see in Ballpark Factor, the Red Sox offense, when you take into account the hitting friendliness of Fenway Park, was actually below league average last year. Fenway Park is a weird one; it has become a dreadful home run park. But it’s still a terrific hitters park, particularly for doubles and batting average. Anyway, there’s every reason to believe the Red Sox will score more runs in 2018 as players like Mookie Betts bounce back from off-years and J.D. Martinez adds power the club lacked with the retirement of David Ortiz. The pitching remains excellent, especially assuming David Price rebounds.

  1. Toronto (Offense -70 RAA, Pitching/Defense: -21 RAA. Run Differential: minus-91 runs).

Ballpark factor: Negligible.

The Blue Jays did add some interesting offensive players like the still-young Randal Grichuk and the veteran Curtis Grandson, but it’s hard to see how that moves the needle enough to fundamentally change the Blue Jays runs scored. Toronto’s pitching was just about league average; it is again hard to see them being all that much better.

  1. Tampa Bay (Offense -69 RAA; Pitching/’Defense: 59 RAA. Run Differential: minus-10 runs)

Ballpark effect: Not huge, but because Tropicana Field is a pitchers park, the offense (-50 RAA) was a little better, the pitching (36 RAA) a little worse.

The Rays were pretty close to league average thanks to some pretty good pitching and defense; it will be interesting to see how that holds up after a little shake-up in the rotation. The already below average offense figures to go backward after the loss of club icon Evan Longoria, all-star Corey Dickerson and sluggers Logan Morrison and Steven Souza.

  1. Baltimore (Offense -20 RAA; Pitching/Defense: -78 RAA. Run Differential: minus-98 runs)

Ballpark effect: Negligible.

The Orioles are hoping that Manny Machado will be great again, Chris Davis will hit bombs again, and that Jonathan Schoop and Adam Jones will basically repeat what they did last year. If all that happens, maybe the offense picks up some runs and becomes better than league average. But even if that happens, it’s unclear how the pitching staff improves upon their massive struggles last year. This team was roughly 200 total runs away from being a contender; it’s hard to find 200 more runs on this roster..

American League Central

  1. Cleveland (Offense: 55 RAA, Pitching/Defense: 199 RAA. Run Differential: 254 runs)

Ballpark effect: Negligible.

Cleveland had a playoff-level offense last year — 50 runs above average being playoff level — because Jose Ramirez had an MVP type season and Francisco Lindor was typically great and Edwin Encarnacion bashed 38 homers. But as you can see so clearly by the numbers, it is pitching that makes Cleveland special. Cleveland’s offense will probably take a step backward after the losses of Carlos Santana and Jay Bruce. They will need to once again have the best pitching in the league to compete with the offensive dominance of the Yankees and Astros.

  1. Minnesota (Offense: 52 RAA, Pitching/Defense: -25 RAA. Run Differential: 27 runs)

Ballpark effect: Negligible.

The Twins scored enough runs in 2017 — fourth in the league — to make up for a shaky rotation and bullpen. They should score even more runs in 2018 assuming that Logan Morrison helps and the wonderful Byron Buxton can build off his superb last couple of months. The question will be that pitching staff — they added starters solid veterans Jake Odorizzi and Lance Lynn, and and will be the fifth team in the last four years to ask the inimitable Fernando Rodney to close games. Can all that push the pitching above league average? It’s an open question.

  1. White Sox (Offense: -57 RAA, Pitching/Defense: -57 RAA. Run Differential: minus-114 runs)

Ballpark effect: Negligible.

As you can see, the White Sox were a well-balanced non-contender in 2017 — they seem to need the same amount of help everywhere. Help seems on the way; there are promising young players everywhere, starting with the brilliantly talented second baseman Yoan Moncada and power starter Lucas Giolito, who has looked great in spring. It’s a process, but you can begin to see the White Sox future take shape, and in baseball these days the future often comes more quickly than expected.

  1. Kansas City (Offense: -61 RAA, Pitching/Defense: -28 RAA. Run Differential: minus–89 runs)

Ballpark effect: Negligible.

The Royals had a struggling offense last year, and that was before losing Eric Hosmer and Lorenzo Cain in free agency. Royals general manager Dayton Moore loathes the idea of being non-competitive even during heavy rebuilding, and so he filled his team with veterans — he brought back Mike Moustakas and Alcides Escobar, picked up Jon Jay and Lucas Duda. The rotation is loaded down with 30-somethings Ian Kennedy, Jason Hammel and Nathan Karns. It’s hard to see any of this changing the run-differential deficit; it will probably be a slog in Kansas City for a while.

  1. Detroit (Offense: -28 RAA, Pitching/Defense: -131 RAA. Run Differential: minus-159 runs)

Ballpark effect: Negligible.

Every sign indicates that it won’t be pretty in Detroit this season. The almost-league average offense numbers from last year is deceiving; it includes the production of Justin Upton, Ian Kinsler and half a year of J.D. Martinez, all of whom are gone. There is hope that the great Miguel Cabrera will hit again, but otherwise this offense seems to be heading South. And there’s no sign that the Tigers pitching staff, dead last in the American League last year, will improve — to the contrary they will be without Justin Verlander. It’s a full-on rebuild and this team is probably barreling head-first into a 200 run-differential.

American League West

  1. Houston (Offense: 133 RAA. Pitching/Defense: 63 RAA. Run Differential: 196 runs)

Ballpark effect: Extreme — Minute Maid Park is actually a very good pitcher’s park. So RE24 shows the offense actually 170 runs above average, far and away the highest total in baseball. The pitching drops to 31 runs above average.

The Astros had the best offense in baseball last year. The thrilling part for Astros fans and the scary part for everyone else is that it was mostly made up of hitters who were 27 or younger — Jose Altuve (27), George Springer (27), Alex Bregman (23) and Carlos Correa (22). The Astros pitching staff was a bit better than league average, which was more than good enough. But now they have Justin Verlander for a full season, plus they added Gerrit Cole. This is pretty close to the perfect roster.

  1. Angels (Offense: -53 RAA. Pitching/Defense: 54 RAA. Run Differential: 1 run)

Ballpark effect: Extreme. Angel Stadium is another good pitcher’s park — the west divisions are filled with them. RE24 shows the offense only 16 runs below average and the pitching only 17 runs above.

The Angels were not really as pitching-heavy as the basic numbers suggest. But whatever last year’s numbers suggest is not as important as the fact that the Angels completely reworked the team, adding Justin Upton, Ian Kinsler and Zack Cozart in the lineup and signing the ultra-intriguing Shohei Ohtani for the rotation. If it all works, you could see the Angels jumping 100 total runs and becoming a big part of the the playoff picture. If it doesn’t work, well, the Angels have been there before. Either way, Mike Trout will keep being awesome.

  1. Seattle(Offense: -13 RAA; Pitching/Defense: -9 RAA. Run Differential: minus-22 runs)

Ballpark effect: Extreme. Another good pitcher’s park; RE24 shows Seattle really had an above average offense (22 runs above) and well below average pitching (42 runs below).

The addition of Dee Gordon could help a pretty good offense become a little bit better, a lot will depend on Gordon’s batting average because he doesn’t walk. In any case, the Mariners season will rely on their pitching staff taking a giant leap forward … and for that to happen, as Mariners general manager Jerry DiPoto says, they need a healthy and vintage year from Felix Hernandez. He was hit with a batted ball this spring which limited his time, but he says he is feeling good and ready to prove that he is still the King.

  1. Texas (Offense: 36 RAA; Pitching/Defense: -53 RAA. Run Differential: minus-17 runs)

Ballpark effect: Negligible.

The Rangers offense was deceptively good in 2017 — deceptive because they were dead last in the league in strikeouts and 13th in batting average, but they still finished fifth in runs scored. Home runs did it. Nine different guys hit 17-plus homers — Joey Gallo mashed 41 of them. pitching was a real problem. Texas hopes that the signing of Doug Fister and the trade for Matt Moore — both accomplished pitchers coming off rough seasons — will turn the tide.

  1. Oakland (Offense: -24 RAA; Pitching/Defense: -63 RAA. Run Differential: minus-87 runs)

Ballpark effect: Extreme. A big-time pitcher’s park masked that the offense was actually slightly above average (4 runs) and the pitching was WAY below (93 runs below, one of the worst totals in baseball).

They Athletics traded for outfielder Stephen Piscotty who could help an offense that really was pretty good last year. The big problem is pitching, and there doesn’t seem any easy answers. The A’s simply need their young starters — particularly Kendall Graveman, Sean Manaea and Paul Blackburn — to take huge steps forward, that is the only way that things work.

National League East

  1. Washington (Offense: 76 RAA; Pitching/Defense: 71 RAA. Run Differential: 147 runs)

Ballpark effect: Negligible.

As you can see, the Nationals are about as balanced as a team can be, which is why they are a runaway favorite to win the division and give themselves another chance to face their postseason demons. The return of outfielder Adam Eaton, the potential ascension at some point this year of the spectacularly talented Victor Robles and the chance for Bryce Harper to stay healthy and blow the minds of all those potential free agent suitors means the offense could be even better. Max Scherzer and Stephen Strasburg’s dueling Cy Young violins suggest the pitching will be at least as good too.

  1.  Mets (Offense: -8 RAA; Pitching/Defense: -120 RAA. Run Differential: minus 128-runs)

Ballpark effect: Citi Field is a pitchers park, so RE24 shows that the Mets offense was really above average (23 runs) and the pitching (minus-159 runs) was legendarily bad.

I had no idea who to put second in this division — the Mets were minus-128 runs last year, the Phillies minus-92 runs and the Braves minus-89 runs. They all have some positives to talk about, and all of them are in a very big hole. I went with the Mets for one reason: The problem with the Mets last year was that their pitching staff was decimated by injury. And, for the moment anyway, their pitching is healthy. Noah Syndergaard is throwing 101 mph again. Matt Harvey says it’s all coming together for him. If that young pitching staff is healthy and dealing and the offense can be at least as good as last year, there could be a huge turnaround.

  1. Philadelphia (Offense: -53 RAA; Pitching/Defense: -39 RAA. Run Differential: minus-92 runs)

Ballpark effect: Negligible.

Things just feel exciting in Philadelphia right now. The Eagles win it all, the Sixers are young and exciting, the Phillies just sign Jake Arrieta and have a hitting folk hero in Rhys Hoskins. The Phillies also signed Carlos Santana, so with some improvement from young players like Hoskins and Nick Williams, this could be a something like a league-average or better offense. The real key, though, will be the pitching: Can Arrieta along with young starters Aaron Nola, Jerad Eickhoff and Vince Velasquez develop into a dominant group? Well, can they?

  1. Atlanta (Offense: -11 RAA; Pitching/Defense: -78 RAA. Run Differential: minus-89 runs)

Ballpark effect: Negligible.

The Braves are building an exciting young offense. Outfielder Ronald Acuna will spend a little time in the minors but based on his extraordinary spring and the dropped jaws of major league scouts, it won’t be long. He will join a hugely gifted lineup with Ozzie Albies, Dansby Swanson, Ender Inciarte and Freddie Freeman, who has developed into one of the best hitters in the game. The pitching is the question; the Braves hope that Julio Teheran finds his All-Star form again and that veterans like my pal Brandon McCarthy can give the Braves quality starts.

  1. Miami (Offense: 35 RAA; Pitching/Defense: -79 RAA. Run Differential: minus-44 runs).

Ballpark effect: Slight adjustments because Marlins Park is a pitcher’s park — with RE24 the offense jumps to 51 runs above and pitching drops to 100 runs below.

This was a legitimately good offense in 2017. But that really has no bearing on this season. MVP Giancarlo Stanton is gone as are Gordon, Marcell Ozuna and Christian Yelich. Those four were roughly 105 runs above average themselves — you can do the math yourself to see what the rest of the team provided. The Marlins didn’t really do anything to improve the troubled pitching staff either. This is a team looking to the future. So what will be worth watching in 2018? Well, talented outfielder Lewis Brinson could be fun.

National League Central

  1. Cubs (Offense: 79 RAA; Pitching/Defense: 48 RAA. Run Differential: 127 runs)

Ballpark effect: Negligible.

The Cubs will be the first to tell you that that they sort of sleep-walked through the first half last season. Even so, they still finished the season well into the run differential playoff zone. The main reason: They are so balanced. And in 2018, they should be better. You would expect the offense to get better naturally; the Cubs are looking for comeback seasons from Kyle Schwarber and Addison Russell in particular.And the pitching could take a big step forward with the acquisition of Yu Darvish and Tyler Chatwood and the bullpen addition of Brandon Morrow.

  1. Cardinals (Offense: 18 RAA; Pitching/Defense: 38 RAA. Run Differential: 56 runs)

Ballpark effect: Negligible.

The Cardinals had the best run differential for any team that didn’t make the playoffs, an unhappy distinction. They shook things up a little bit in in the offseason by dealing Stephen Piscotty and Randal Grichuk, by acquiring slugger Marcell Ozuna and by giving centerfield to the dynamic Tommy Pham. The pitching staff is more or less the same from a year ago, which isn’t a problem as the pitching was pretty good in 2017, The Cardinals could use a boost from Cardinals legend Adam Wainwright and/or Miles Mikolas, a former Major Leaguer who found his game and rhythm in Japan.

  1. Milwaukee (Offense: -11 RAA; Pitching/Defense: 46 RAA. Run Differential: 35 runs)

Ballpark effect: There’s a moderate effect because Milwaukee is a surprisingly good hitters’ park. The offense was probably a bit worse than the raw numbers suggest (RE24 says 27 runs below average) while the pitching was a bit better (68 runs above).

The Brewers were one of the surprise teams in baseball last year, and a big reason was the way the pitching staff came into its own. The emergence of starters Zach Davies, Jimmy Nelson and Chase Anderson plus closer Corey Knebel was game-changing, and now the Brewers have also added Jhoulys Chacin and Wade Miley. The offense was not quite good enough to pull off the miracle last year; now they have added Christian Yelich and Lorenzo Cain. The Brewers and Cardinals could be fighting hard for that 100-run differential and a wildcard spot.

  1. Pittsburgh (Offense -75 RAA; Pitching/Defense: 12 RAA. Run Differential: minus-63 runs)

Ballpark effect: Negligible.

The big problem with Pittsburgh last year was the offense … and in the offseason they dealt away their most iconic player Andrew McCutchen. Can the Pirates who remain find enough runs to make up last year’s deficit? It’s hard to see how: They will need huge steps forward from the Joshes, Bell and Harrison, and they need Starling Marte to come back and newly acquired Corey Dickerson to hit a lot. It’s still a reach. Prediction: The pitching staff will be better than you think, and that’s even with the loss of Gerrit Cole.

  1. Cincinnati (Offense: 10 RAA; Pitching/Defense: -126 RAA. Run Differential: minus-116 runs)

Ballpark effect: Negligible.

The Reds offense was right around league average last year thanks to the overwhelming excellence of Joey Votto along with a cast of power hitters who you might not yet know — Scott Schebler (30 homers), Eugenio Suarez (26 homers, 115 OPS+), Adam Duvall (31 homers, 99 RBIs), Scooter Gennett (27 homers, four in one game), etc. The pitching was a disaster movie for most of the year, but things did pick up some toward the end of the season as young Luis Castillo and Sal Romano showed promise. There was some buzz around spring training that the Reds’ pitching will come quickly and the team could surprise in 2018. Hey, don’t blame me, I’m just passing along the buzz.

National League West

  1. Dodgers (Offense: 27 RAA; Pitching/Defense: 163 RAA. Run Differential: 190 runs)

Ballpark effect: Not as big as you might think, but because Dodger Stadium is a pitchers park it would be easy to miss how good the offense really was (RE24 says 58 runs above).

The offense was better than the pure runs-scored would suggest and lineup depth should still be a strength, even with the sad loss of Justin Turner to a broken wrist. But clearly the Dodgers’ power comes from that pitching staff and the team’s defense. The Dodgers added depth to the bullpen by picking up Scott Alexander in a deal, but the rest of the names — Clayton Kershaw, Kenley Jansen, Rich Hill, Alex Wood, etc. — will look familiar. The Dodgers sure look like one of baseball’s playoff locks.

  1. Arizona (Offense: 69 RAA; Pitching/Defense: 84 RAA. Run Differential: 153 runs)

Ballpark effect: Extreme. RE24 says that offense was 36 runs above average and the pitching a jaw-dropped 127 runs above average.

The offense was good in 2017, but make no mistake: The thing that made the Diamondbacks a terrific team in 2017 was that pitching. .Chase Field is one of the best hitters parks in baseball, it is basically Coors Field South, and for the pitchers to allow 84 fewer runs than average was breathtakingly good. The emergence of Robbie Ray to join Zack Greinke as aces in the rotation was probably the key to the whole season and will be a key again as the Diamondbacks try to repeat their success. Even without J.D. Martinez, you would expect this team to score runs.

  1. Colorado (Offense: 81 RAA; Pitching/Defense: -14 RAA. Run Differential: 67 runs)

Ballpark effect: Ultra extreme. Coors Field turns everything upside down. You look at the raw runs above average and you would think the Rockies had a great offense and decent pitching. The opposite was true. RE24 shows the Rockies offense was actually 20 runs BELOW average while pitching was 101 runs above.

In context, the Rockies pitching was third best in the league, behind only the Dodgers and Diamondbacks. The offensive numbers are gaudy. Nolan Arenado looks to become just the 11th player — and the first since Ryan Howard — to hit 35 homers and drive in 130 runs four years in a row. Charlie Blackmon looks to follow up a jaw-dropping season where he hit .331, slugged .601 and scored 137 runs. But it is the young rotation and the bullpen — now locked down by closer Wade Davis — that will determine if the Rockies can improve that run differential and get back to the playoffs.

 

  1. San Francisco (Offense: -104 RAA; Pitching/Defense: -33 RAA. Run Differential: minus-137 runs)

Ballpark effect: Negligible.

Every single thing that could have gone wrong for the Giants went wrong. Nobody hit. Brandon Belt led the team with 18 home runs. Madison Bumgarner had a freak injury. The bullpen was a in disarray. The Giants worked hard to fixit all in one offseason — they picked up longtime stars Evan Longoria and Andrew McCutchen as well as centerfielder Austin Jackson. They plan to keep Bumgarner away from any freak possibilities, and they also want to believe closer Mark Melancon is finished with his odd dead-arm issues. Can this and some good luck overcome this gigantic deficit?

  1. San Diego (Offense: -139 RAA; Pitching/Defense: -73 RAA. Run Differential: minus-212 runs)

Ballpark effect: Petco is a severe pitchers park, but it doesn’t really change the overall story with the Padres. The offense was a bit better (RE24 says 119 runs below), the pitching a big worse (100 runs below) but really, does it matter?

The Padres did nothing well in 2017 and even with some activity during the offseason — the big signing of Eric Hosmer in particular — it seems unlikely that the Padres can make huge strides this year. But here’s the good news: With MLBPipeline’s No. 1 farm system, San Diego appears set up well for the future. There are some interesting players to watch even this year, beginning with Hosmer and his former minor-league teammate Will Myers. Outfielder Manuel Margot, who flashed power and speed as a rookie and has potential to be a spectacular player. And it will be fun to keep any eye on the minor leagues.

 

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19 Responses to The Run Differential Breakdown

  1. Paul Schroeder says:

    Well, ummm, OK. Thanks for that.

  2. Darrel says:

    I’m sure every teams fans will chime in on this but I disagree on the Blue Jays blurb. Now keep in mind I’m not expecting a real contender here but adding the 2016 ERA champ back into the rotation, having their MVP 3B healthy all year, and increasing the depth at nearly every position(so as to avoid playing Ryan Goins and Darwin Barney nearly full time) should make a pretty massive difference. I could easily see both sides of the equation moving back to league average. That still leaves you a $10 cab ride from the playoffs but it aint nothin.

  3. AndrewL says:

    I don’t know if other readers will agree, but I am tired of the Michael Schur “Hot Takes” Poscast persona extolling the virtues of pitcher wins and grit. Simply not funny anymore. And boring. It ruined what could have been an interesting baseball preview podcast with Keith Law.

    • mikeski says:

      I don’t know that I would go so far as to say that it “ruined” the Poscast, but a little of that goes a long way. Especially since Schur is a knowledgeable guy who has something to add to the discussion. A couple of well-placed instances of Hot Take Mike might be more effective.

  4. Marc Schneider says:

    What I wonder is whether the schedule of different teams affect their run differential. Since teams play unbalanced schedules, teams in stronger divisions presumably face better teams more often than teams in weaker divisions. Would this affect their expected run differential? It seems like it would but maybe the effect somehow balances out. The significance would be if you evaluate a team based on their run differential, could it be misleading? Of course, this only applies to 1969 on and especially 1994 on as prior to that teams in each league played pretty much the same schedule.

  5. Average Intelligence Reader says:

    To put the pitching runs in context, a starter who throws 207 innings in a season would give up 23 runs per point of ERA (I’m ignoring unearned runs for simplicity). So if you upgraded from a 5th starter type (with a 5.00 ERA) to a front of the rotation guy (with a 3.00 ERA), that would get you a 46 run improvement over the course of the year.

  6. MikeN says:

    “Runs scored ^2 / runs scored ^2 + runs allowed ^2 = estimated team’s winning percentage.”

    I think it should be Games Won/ Games Played.

    • Jeff says:

      It should be the following.
      Runs scored ^2 / (runs scored ^2 + runs allowed ^2)
      PEMDAS, dude.

      However, I am from the old school and I prefer your formula. The Orioles were slighted for many years based upon this type of analytics.

  7. Joey says:

    Hey Joe, always appreciate your baseball perspective. Here’s a question, you wrote “Fenway Park is a weird one; it has become a dreadful home run park…”

    How can a park (without changing dimensions, moving fencing in or out, etc) change over time?

    • J Hench says:

      A park is a good hitter’s or pitcher’s park (or good HR Park) in relation to other parks.

      If I have 5 parks in my league and they are Fenway, Tropicana, Safeco, Oakland, and San Fran, then Fenway is probably going to be the best HR Park. But add in Camden Yards, New Yankee Stadium, Coors, whatever bank AZ is named after now, Citizens Bank, and suddenly, Fenway is middle of the pack at best.

    • invitro says:

      “How can a park (without changing dimensions, moving fencing in or out, etc) change over time?” — Weather. The biggest factor in whether a park is a hitters’ or pitchers’ park is altitude, and the 2nd biggest factor is weather (I think the 3rd is foul territory, and the 4th is… finally… the distance to the outfield fences, which probably used to be the only one of these that was commonly considered to be a factor). The altitude doesn’t change, but it’s common for a city to have a significantly hotter or cooler summer than usual.

      I don’t know if this is the case for Fenway, but has Fenway really been that much of a home-run park recently? I thought it was great mainly for doubles by RH hitters.

    • AJ Taylor says:

      The steady building-up of the pressbox/VIP lounge structure behind home plate since the 1980s has altered the wind patterns inside the park somewhat and really cut down on the wind blowing out from home plate. Over the past few years it’s played as about a neutral home run park for right-handers, but an absolutely dreadful park for lefties, as whatever cheap home runs the Pesky Pole generates are more than cancelled out by the long distance to right-center and the Triangle.

      David Ortiz is a pretty good illustration of Fenway’s effects; overall, he hit nearly 40 points better at home with far more doubles and triples, but hit 300 road home runs, as opposed to 241 at home.

  8. PhilM says:

    For something along these lines, if only tangentially and providing an historical context, I humbly submit my SABR “By the Numbers” article from 2003, on page 15 (two addresses and emails ago — can it have been that long?!):

    http://www.philbirnbaum.com/btn2003-02.pdf

    It’s nice to see run differential getting a little love. . . .

  9. larry shea says:

    How can you have 10 pitcher’s parks, including 5 “extreme” yet only 4 hitter’s parks, including 2 “extreme?”

  10. Unvenfurth says:

    So Cincinnati, Philadelphia and Yankee Stadium are not hitter’s parks?

    • invitro says:

      The last three (one-year) park factors for each are:
      – Cincinnati: 101, 99, 103
      – Philly: 101, 92, 104
      – Yankees: 104, 105, 101

      Milwaukee is 104, 99, 103 so maybe Yankee Stadium should be listed as a moderate hitters’ park (as Milwaukee seems to be).

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