ROTISSERIE: Divisional advantage for pitchers

As we head into the busiest draft weekend of the season, many fantasy owners are anxiously trying to finalize their decisions about players, especially pitchers. BaseballHQ.com has many excellent tools to help make those decisions, and many excellent analysts to provide advice on that point.

To all of the assembled wisdom at the site, we can add one more tool: the divisional advantage or disadvantage. While not as prescriptive as the core skills assessments and StatCast metrics that have come to define pitcher ability, this new information might serve as a way to “tiebreak” between pitchers who seem otherwise indistinguishable.

The idea is based on something first proposed by Michael Salfino of The Athletic. The idea is to take advantage of baseball’s severely unbalanced scheduling rules, specifically the rule that says teams play other teams insidetheir divisions far more often (19 times each) than they play any of the teams outsidetheir divisions.

Take the Toronto Blue Jays. They will play:

  • AL East opponents 19 times each, 76 games in all
  • AL Central opponents 7 times each, 35 games
  • Four AL West opponents (TEX, HOU, OAK, SEA) 6 times each, 24 games
  • One AL West opponent (LAA) 7 times, 7 games
  • Four NL West opponents (COL, ARI, LA, SD) 3 times each, 12 games
  • One NL West opponent (SF) 4 times, 4 games
  • One NL East opponent (ATL) 4 times, 4 games

The out-of-division games rotate around, and the interleague games also rotate, with some permanent interleague series to exploit geographic or historic rivalries.

Here’s the thing: Not all divisions are created equal when it comes to their offensive punch. And the canny fantasy owner might be able to take advantage.

The earlier research used the previous year’s OPS for all the divisions, and looked for divisions that had more than their share of weak hitters relative to league average. This brief followup study will do similar work, but with two differences. First, because the previous year’s divisional OPS results will swing from year-to-year due to personnel changes, the study uses this year’s BHQ projections for individual hitters, combined into team-level OPS outcomes. Second, each division’s combined OPS results are recalculated to exclude each team’s OPS when that team is being considered. That is, looking at the Blue Jays’ intra-divisional OPS excludes the Jays themselves, since their pitchers don’t get to pitch to their hitters.

Once we see the division-level situations, we’ll “zoom in” to assess some results team-by-team to focus our attention more precisely.

Research Results

First, here are the OPS and R/G results by division, from lowest (best for opposing pitchers) to highest opposition OPS:

DIV        OPS   R/G
=====================
AL CENT   .722   4.86
AL EAST   .745   4.75
NL EAST   .747   4.39
AL WEST   .752   4.65
NL WEST   .752   4.43
NL CENT   .772   4.42

At first blush, it looks like the obvious ploy is to target AL Central pitchers, or at least to give them a longer look in comparison to, say, NL Central pitchers of similar skills. But that analysis, while mostly solid, ignores the effect of each team on the overall divisional OPS. Indeed, when we look at the divisional OPS results with the team’s own OPS backed out of the total, the results are different:

             |-Div Opp-|
Team          OPS   R/G
========================
NYY   AL-E   .730   4.59
BOS   AL-E   .734   4.64
WAS   NL-E   .737   4.29
COL   NL-W   .738   4.25
MIN   AL-C   .740   4.54
PHI   NL-E   .740   4.34
ATL   NL-E   .742   4.38
LA    NL-W   .744   4.21
CLE   AL-C   .744   4.41
HOU   AL-W   .746   4.69
TOR   AL-E   .747   4.85
TAM   AL-E   .748   4.80
NYM   NL-E   .749   4.42
LAA   AL-W   .750   4.85
SEA   AL-W   .753   4.97
SD    NL-W   .753   4.27
OAK   AL-W   .753   4.83
DET   AL-C   .754   4.57
CHW   AL-C   .756   4.60
TEX   AL-W   .758   4.93
ARI   NL-W   .758   4.39
KC    AL-C   .759   4.61
BAL   AL-E   .765   4.86
MIA   NL-E   .765   4.52
SF    NL-W   .766   4.35
CIN   NL-C   .767   4.43
MIL   NL-C   .767   4.44
CHC   NL-C   .771   4.46
STL   NL-C   .771   4.42
PIT   NL-C   .782   4.59

The rule is that the higher up the list, the greater the team’s pitching advantage because of the relative offensive weakness of the otherteams in the division. So while the overall results suggests AL-Central pitchers because of the division’s overall .722 OPS, the team-by-team results suggest looking first at pitchers in NYY and BOS, because those teams are the main reason the AL-East has a .745 OPS—without them, the division pOPS of the remaining three teams is just .711 because TAM (.730 pOPS), TOR (.737) and, especially, BAL (.667) project to be so offensively weak.

Similarly, the NL-West projects to a high pOPS, but that’s because the thunderous LA (.785 pOPS) and COL (.810) offenses pull up the division average. In fact, COL and LA pitchers should be targets in this analysis because they get 57 shots each at SD (.748 pOPS), ARI (.724) and SF (.697).

On the other end of the scale, not even the presence of the bloodless Pirates (.729 pOPS) can recommend the pitchers of the NL-Central, who otherwise have to face the strong offenses in CIN (.790 pOPS), MIL (.789), CHC (.774) and STL (.773). All of those offenses are above the MLB pOBP of .757.

In another example of more focused attention, while the AL Central is generally weak, the top beneficiary of that weakness is MIN. Only the Twins, at .763, are above the .757 MLB pOBP, while all four of their opponents are well under, including one team under .700 pOPS (KC at .689) and two more barely over (CHW at .700 and DET at .709). CLE also gets their 57 shots at those weak offenses, but must contend with MIN’s above-average offense those 19 times.

And finally, while the unbalanced schedule obliges us to look at intra-divisional matchups, some teams’ pitchers also benefit from playing weak non-divisional opponents like BAL (.667 pOPS) MIA (.673), SF (.697), and KC (.689). Since all AL and NL teams get either six or seven games against other non-divisional in-league opponents, there is no advantage, but the interleague matchups are not balanced at all, rotating year-by-year so that each AL team faces only a few NL teams and vice-versa. This year, for example, only the NL East teams (plus the odd “rivalry” team) get to feast on weak AL-Central opponents.

Caveats and Conclusion

This analysis depends on the BHQ projections, so is subject to the usual cautions about the error bars inherent in all projections. As well, no opponent-matchup analysis should induce a fantasy owners to prefer one pitcher over another solely or even primarily because of a divisional matchup advantage. The matchups might be a reason to prefer Jose Berrios in the weak AL Central over a similarly skilled pitcher like, say, Jameson Taillon in the much tougher NL Central. But it is no reason to prefer Berrios to Jacob deGrom, even with Berrios’s 9-point pOPS divisional advantage. As noted earlier, think of these results as a guide to breaking ties between equally skilled pitchers. 


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  For more information about the terms used in this article, see our Glossary Primer.