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The Saber's Edge: BABIP Swings

Jeff Zimmerman

Zimmerman writes analytics-focused baseball and football articles for RotoWire. He also handles scouting and reporting for and contributes to, and Jeff is also a two time FSWA award winner, including the 2016 Football Writer of the Year award.

Lonnie Chisenhall is finally living up to his previous prospect status (he was ranked #31 overall in 2010 and #25 overall in 2011 by Baseball America) by hitting .317 so far this season with nine home runs. Chisenhall has seen his AVG jump nearly 100 points from a .225 value in 2013. Most of the increase is from a 120-point jump in his BABIP (.243 to .363). This jump seems fairly substantial, but how common is such a jump? This week, I will look at similar swings in BABIP from year-to-year to determine how often it happens, and how those players have historically performed over the rest of the season.

Chisenhall's jump in BABIP is the biggest in over two decades. Looking at players with a minimum of 300 PA in back-to-back seasons, his 120-point jump is the largest since Andres Galarraga had a 122-point jump from the 1992 to the 1993 season. In fact, only 11 other hitters, besides Galarraga and Chisenhall, have ever seen a 100-point jump since Galarraga's season.

Jay Bruce: 2009 to 2010 +0.113
Matt Williams: 1994 to 1995 +0.112
Ray Durham: 2007 to 2008 +0.112
Justin Morneau: 2009 to 2010 +0.112
Desi Relaford: 2000 to 2001 +0.109
Jarrod Saltalamacchia: 2012 to 2013 +0.106
Melvin Mora: 2002 to 2003 +0.106
Casey Kotchman: 2010 to 2011 +0.105
Scott Brosius: 1997 to 1998 +0.103
Paul Sorrento: 1995 to 1996 +0.102
Bret Boone: 1993 to 1994 +0.100

Chisenhall's increase puts him in a small group of players. To put the group into perspective, here are the percentage of players from 1992 to 2013 at different BABIP levels broken down into 25 point intervals.

Change in BABIP: % Likelihood
> 100: 0.3%
75 to 100: 1.6%
50 to 75: 5.2%
25 to 50: 13.5%
0 to 25: 25.5%
0 to -25: 27.4%
-25 to -50: 17.2%
-50 to -75: 7.2%
-75 to -100: 2.1%
< -100: 0.2%

Chisenhall is beating the odds quite a bit with the BABIP increase over 100 points. Out of every 1,000 match paired seasons, only three hitters should expect such a jump.

So, we all now know Chisenhall is a special case, but what can we expect from him going forward? How often do players with a high BABIP early in the season keep it up as the season goes on? To find the answer to this question, I looked at the player's first half BABIP compared to the season before. Then, I found the player's BABIP for the second half of the season. For these values, I looked at all seasons between 2002 and 2013 with a min 200 PA in the first and second half, and 300 PA in the previous season.

I grouped the output into 25-point blocks according to increase from the previous season to the current season. Also, I calculated the average BABIP for the season's second half.

Change in BABIP: Previous Season to 1H, 1H to 2H
> 100: +0.113, -.057
75 to 100: +.082, -0.048
50 to 75: +.059, -.036
25 to 50: +.035, -.018
0 to 25: +.011, -.010
0 to -25: -0.013, +.010
-25 to -50: -0.036, +.020
-50 to -75: -0.061, +.040
-75 to -100: -0.085, +.046
< -100: -.110, +.067

There's no real surprise with any of these values. Players who have higher BABIPs will see their values regress down to their previous norms. The players don't go all the way down for a couple possible reasons. Their increase BABIP may be the combination of increased luck and a new talent level. Players do improve. Also, the previous season's value may be an all-time low before the player bounced back. Chisenhall has been volatile in the BABIP department throughout his career:

Season: BABIP
2011: .299
2012: .300
2013: .243
2014. .363

From 2012 to 2013, he saw a 57-point drop. He came back to his previous BABIP value and then some in 2014. Since I used first and second-half values and we are into the season's second half, here are his 2014 BABIP values:

1st: .367
2nd: .308
Difference: -.059

His second-half BABIP is down to his 2011 and 2012 values. The drop is almost identical to the historic average drop of -.057.

Few leagues that use BABIP as a category exist, but the key BABIP related stat for most fantasy owners is batting average (AVG). Here are the average amounts of AVG change depending on how much a player's BABIP jumps compared to the previous season. Remember, the table is BABIP change, then AVG and AVG change.

Change in BABIP: Previous Season to 1H, 1H to 2H
> 100: +.071, -.030
75 to 100: +.063, -.036
50 to 75: +.047, -.029
25 to 50: +.027, -.014
0 to 25: +.008, -.008
0 to -25: -.010 +.006
-25 to -50: -.028, +.016
-50 to -75: -.046, +.031
-75 to -100: -.065, +.036
< -100: -.089, +.055

For Chisenhall, he is seeing a drastic decline from a .328 AVG to a .211 AVG. The main reason for the drop, besides just the BABIP decline, is that his K% has gone from 15% to 25%.

Chisenhall isn't the only player with an extreme change in BABIP this season. Here are a few players who have seen their BABIP change, and some thoughts on each.

Josh Hamilton
2013 BABIP: .303
2014 1H BABIP: .412
Diff: +.109
2014 2H BABIP: .400

Hamilton may be one of the few hitters who may not see his BABIP decline too much. He did have a near .400 BABIP in 2010, so a high BABIP isn't out of the range with his skill set. He is struggling to hit for since have his thumb surgery, however. Hamilton's ISO (.141) is at a career low and he is on pace to hit around only 10 homers. It may be prudent to move him while he has the high-ish AVG and before he becomes void of value.

Conor Gillaspie
2013 BABIP: .270
2014 1H BABIP: .379
Diff: +.109
2014 2H BABIP: .267

Nothing in Gillaspie's past points to him supporting such a high first-half BABIP. His BABIP coming into 2014 was .262 which is almost the same as his second-half value. Sell if you can get anything of value while he still has the .300 average. Once it drops below .300, he will look much less appealing.

Jhonny Peralta
2013 BABIP: .374
2014 1H BABIP: .275
Diff: -.099
2014 2H BABIP: .400

Peralta isn't under-producing this year, he is just coming off a career season in 2013 for BABIP. One thing he can't seem to do recently is hit near his career BABIP of .313. He is either way above or below. Here are his last few BABIP values:

2010: .275
2011: .324
2012: .275
2013: .374
2014: .280

Other than expecting some upward BABIP regression, he has the potential to hit a few more home runs which is more than can be said for most shortstops.

Besides these few players, here is the complete list of players for reference. As always, feel free to chime in with questions in the comments section below.