Friday 25 July 2008

Opportunity bunts!

In connection with a Diamond Mind Baseball league I play, I was looking at Jerry Royster's brief major-league managerial career. (He's now big in Korea.) The scuttlebutt had him as an old school manager who valued the bunt and the little things - taken the extra base, moving the runner over, etc

Obviously, the simple way to look at such things is to count up all the sacrifice hits and see who bunted the most. By this measure, Royster stacks up pretty well, being in the top 25 percent of NL managers that season. (The DH-rule means comparisons across leagues don't apply as oftentimes the bunt is the default move when the pitcher is at bat.)

Team         SacHit     SB+CS        OBP
MON 108 182 .334
CIN 95 168 .330
StL 83 128 .338
MIL (Royster) 79 144 .320
CHI 78 84 .321
NY 75 129 .322
SF 68 95 .344
PIT 68 135 .319
ATL 67 115 .331
PHI 67 147 .339
LA 67 133 .320
HOU 64 98 .338
ARI 62 138 .346
FLA 59 250 .337
COL 49 186 .337
SD 45 115 .321

(Royster didn't particularly steal much, so let's put that question to one side for today.) Royster was fourth overall, but there was some bunching so some of that might be down to opportunities.

Exactly! Not only do we need to know how many times Royster bunted, to get an idea whether he has any tendency to bunt, but we also need to know how many opportunities he had to order a bunt. To give you some guide already, I've listed the team OBP above. You can see that the Brewers were near the bottom in that category, so Royster's high bunt total and low OBP probably means we're going to see a further adjustment upwards.

To do this, I subtracted from the number of hits, the number of extra-base hits, stolen bases and caught stealings; then I added walks and hit batsmen. (This is not perfect. One also would like to know how many wild pitches and balks were involved in moving the runner over.) After that, you can divide the number of sacrifice hits by the number we'll call MO1 (Men on 1st). I'll call the resulting number the bunt percentage.
Team        SacHit      MO1      BuntPct
MON 108 1373 .079
CIN 95 1380 .069
MIL (Royster) 79 1343 .059
StL 83 1470 .056
CHI 78 1408 .055
NY 75 1409 .053
PIT 68 1350 .050
LA 67 1342 .050
PHI 67 1443 .046
ATL 67 1456 .046
SF 68 1518 .045
FLA 59 1381 .043
HOU 64 1501 .043
ARI 62 1537 .040
COL 49 1429 .034
SD 45 1447 .031

It changes things a little, although you can see from this that the simple total of sacrifice hits is a pretty good guide to how much a manager calls for the bunt. The main effect is to show how much Dusty Baker (with the Giants), Jimy Williams (with the Astros) and Bob Brenly (with the Diamondbacks) didn't bunt, relative to their opportunities. However, we're still not done with what these statistics can show us.

Using the standard deviation (the average amount that any of the bunt percentages is away from the mean), we can get an idea of whether Royster's .059 was particularly extreme behaviour. The standard deviation for this list is .012. The average is something like .050. Therefore, if the difference between a team's bunt percentage and the league average is more than .012, that's an example of extreme behaviour.
Team      Deviation   Number of StDev
MON .029 3
CIN .019 2
SD -.019 2
COL -.015 2
MIL (Royster) .009 1
ARI -.009 1
StL .007 1
HOU -.007 1
FLA -.007 1
CHI .006 1
SF -.005 1
ATL -.004 1
NY .003 1
PHI -.003 1
PIT .001 1
LA .000 1

So, Royster didn't really deviate all that much from the average NL manager in 2002. He was headed in that direction, but didn't quite make it. The real extremists when it came to the bunt were Frank Robinson, who bunted an awful lot (into the third standard deviation!), and Bruce Bochy and Bob Boone, at opposite ends of the spectrum.

There's another issue one should bear in mind when reading this sort of stuff. Royster's team wasn't particulary good, finishing with over 100 losses (94 down to Royster's tenure) and having the worst offense in the league, bar one (Pittsburgh). In such circumstances, a manager may call more bunts, steal more and go with the hit and run in order to make something happen, or light a spark under the team. It rarely works, but we tend to fidget more when we're unhappy than when we're happy. Because Royster's major-league career is so short, we'd really like to know more about his minor-league one. Perhaps, one day, when I assemble the statistics, we'll be able to shed some more light on whether, for Jerry Royster, opportunity doesn't knock but bunts.

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