Baseball Q

What is the historical differential in batting average between home games and away games?

I know that the Cubs and the Rockies have a different value than the Yankees and the Reds, but I just want to know the average over time.

I had another Q but Baseball Prospectus had it teed up. It was about the record for bunt base hits in a season, plus the average sucess rate. In case you haven’t been paying attention to Willie Taveras.

Do you mean the aggregate total of all major league batters in history?

Gosh, I’m not sure that would be an easy question to answer.

The folks at Retrosheet could provide those numbers, at least for the years since 1950. There have been many studies of home field advantage (here’s just one example, and Cecil himself addressed the issue just six weeks ago.

Mist studies that I’m aware if look at wins and losses, rather than batting average, because fluctuations in batting average are largely affected by the dimensions and conditions at various parks. I’m not sure that looking at home and away batting averages in the aggregate will yield any meaningful insight.

It is a foggy area of research, to be sure.

I would bet that 90% of the players with the highest difference between home and away average would be Colorado Rockies players. I don’t think Todd Helton should even be considered for the HOF after playing most of his career there- its like comparing stats of an NFL and arena football QB.

The normal HFA for batting average is somewhere around 5-10 points. This has bedeviled researchers trying to ascertain how much a ballpark helps or hurts a player. E.g. if you have the same average both home and away the home ballpark is hurting you slightly.

Active players, sure. Through last night , Helton’s career average is .367 in Colorado and .293 everywhere else.

Here are some home/road splits for a few notable players (source Total Baseball, first edition):

Henry Aaron 303/306
Roberto Clemente 329/306
Ty Cobb 370/363
Joe DiMaggio 315/333
Jimmie Foxx 345/307
Lou Gehrig 329/351
Al Kaline 303/292
Nap Lajoie 353/324
Mickey Mantle 305/291
Willie Mays 302/301
Stan Musial 336/326
Mel Ott 297/311
Pete Rose 310/296
Babe Ruth 347/338
Tris Speaker 365/325
Ted Williams 361/328
Carl Yastrzemski 306/264

I suspect that that gap has been narrowing for the last six years (post-humidor). This season he is hitting .309 at home, and .285 on the road. Helton isn’t a HOF contender under the new conditions. His numbers have really dropped the last few years.

Thanks for the answers, it was just something that popped into my mind while listening to a game on the radio yesterday. I would have thought that the difference was closer to 20-25 points.