The MLB postseason had a power surge on Monday. Yesterday’s four division series games featured a long ball barrage that set a myriad of records, including the most home runs and runs scored in a single day of postseason play. Who said the playoffs were all about small ball?
To be fair, before Monday’s outburst, both runs and home runs had been in short supply in October. The 21 homers and 61 runs scored nearly doubled the cumulative output for each statistic, so yesterday’s breakout hardly represents a trend. However, that doesn’t mean the small ball narrative has validity. Although home runs aren’t likely to be as plentiful during the rest of the month, history suggests they will continue to play a significant role throughout the rest of the postseason.
Rate of Runs Scored via the Home Run, Regular Season vs. Postseason, 1995 to 2015YTD
Note: PS = Postseason; RS = Regular season.
Source: Baseball-reference.com
Since the start of the wild card era in 1995, home runs have accounted for 38.6% of all runs scored during the post season. Contrary to conventional wisdom, which suggests hitting home runs becomes more difficult in October, that’s three percentage points higher than the MLB regular season rate. When compared to the regular season performance of playoff teams, the gap narrows, but remains at two percentage points. What’s more, the yearly fluctuations have a similar bias. Compared to the entire league, 15 of 21 seasons (including year-to-date 2015) have featured a higher percentage of runs scored on homers in the postseason. Relative to playoff teams only, the ratio actually increases to 16 of 21. In addition, the differential has routinely been larger when it favors the postseason. Whereas there have been seven seasons since 1995 with at least a five percentage point increase in postseason runs produced by the long ball (six seasons when comparing to playoff teams’ regular season output), only two years (2000 and 2012) have featured a decline of a similar magnitude.
Home Runs Per Game: Regular Season vs. Postseason, 1995 to 2015 (ytd)
Note: PS = Postseason; RS = Regular season. Averages are per team per game.
Source: Baseball-reference.com
Although home runs have had a greater impact on the postseason during the wild card era, they haven’t been more plentiful. Since 1995, MLB has averaged 1.04 home runs per team game during both the regular season and postseason, while playoff teams have checked in slightly higher with an average of 1.12 round trippers before October. Again, there have been yearly fluctuations, but in only seven seasons (whether compared to the regular season of all teams or just those who made the playoffs) has the difference been greater than two-tenths (or an extra home run every five games).
Runs Scored Per Home Run: Regular Season vs. Postseason, 1995 to 2015 (ytd)
Note: PS = Postseason; RS = Regular season.
Source: Baseball-reference.com
Not only have post season home run totals fallen in line with regular season output, but so too has the average impact. Since 1995, a post season round tripper has yielded an average of 1.6 runs, which matches the per home run average during the regular season for both the entire league and the subset of playoff teams. However, this equivalence is a little misleading. With the exception of 1998 and 1999, when the relationship peaked in the opposite direction, postseason home runs have regularly yielded a smaller payload. So, if teams aren’t hitting more home runs in the postseason, nor scoring more runs on the average round tripper, why has the long ball become a more meaningful contributor to offensive production in October?
Runs/Game via Home Runs and Non-Home Runs: Regular Season vs. Postseason, Cumulative 1995 to 2015 (ytd)
Note: Regular season data is for playoff teams only. Averages are per team per game.
Source: Baseball-reference.com
As it turns out, the convention wisdom is not only wrong, but ironically so. The reason home runs represent a larger percentage of scoring during the postseason is because runs produced via other means decline on a greater relative basis. In aggregate since 1995, runs scored on homers have fallen by 10% in the postseason, while all other forms of run production have dropped by nearly twice as much. In some ways, this should be intuitive when you consider that better pitchers are probably more likely to make one mistake than several, and better hitters are likely more apt to hit that mistake out of the park.
Various Small Ball Tactics: Regular Season vs. Postseason, Cumulative 1995 to 2015 (ytd)
Note: Averages are per team per game.
Source: Baseball-reference.com
Although some fans and media probably won’t be convinced that small ball isn’t more effective in October, it seems as if the teams themselves have come to that conclusion. Putting efficacy aside, anecdotal evidence suggests these tactics are not being employed more frequently in October. Of course, that doesn’t necessarily mean more small ball wouldn’t lead to increased run production, but it does suggest the current environment is not compelling their use.
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