Juicing the bases early, part II

As a followup to my last post, I am doing another study with a few changes. First, I added 1997 and 1998 to the sample. I would have added 1999 too but RetroSheet apparently doesn't have it for some reason. Second, I fixed some minor query problems that were causing me to double-count PA's with balks and pickoffs. Third, I altered my SQL procedure to output the results broken down by innings and score differential.

So, just to recap:

We are looking for plate appearances in completed games played between 1997-2007 for which there is pitch data, where:

- There are runners on second and third, one out.
- Prior to the seventh inning.
- The batter is in one of the top-six spots of the order.
- The batter is not Barry Bonds.

We are seperating PA's into two types: PA's where there is an obvious intentional walk (four straight intentional balls,) and PA's where there is not. Then, we are looking at how often teams wind up winning the game when they walk the batter vs. when they let him hit.

The following is the results:

Inning	Score Diff	No-IBB Record	IBB Record	No-IBB W%	IBB W%	Diff	IBB Gain
1	-5	0-0	0-0	0.000	0.000	0.000	0.000
2	-5	2-21	0-4	0.087	0.000	-0.087	-0.348
3	-5	2-9	0-0	0.181	0.000	-0.181	0.000
4	-5	2-43	0-7	0.444	0.000	-0.444	-0.311
5	-5	2-26	0-6	0.071	0.000	-0.071	-0.429
6	-5	0-44	0-14	0.000	0.000	0.000	0.000
1	-4	0-1	0-0	0.000	0.000	0.000	0.000
2	-4	4-45	1-7	0.082	0.125	0.043	+0.347
3	-4	4-20	0-4	0.167	0.000	-0.167	-0.667
4	-4	4-63	0-8	0.060	0.000	-0.060	-0.478
5	-4	2-57	1-10	0.034	0.091	0.058	+0.627
6	-4	1-69	0-9	0.014	0.000	-0.014	-0.129
1	-3	0-0	0-0	0.000	0.000	0.000	0.000
2	-3	19-77	0-11	0.198	0.000	-0.198	-2.177
3	-3	11-60	1-17	0.155	0.056	-0.994	-1.789
4	-3	13-90	2-3	0.126	0.400	0.274	+1.369
5	-3	4-74	5-33	0.051	0.132	0.080	+3.051
6	-3	6-66	0-30	0.083	0.000	-0.083	-2.500
1	-2	32-109	2-3	0.227	0.400	0.173	+0.865
2	-2	31-104	1-3	0.230	0.250	0.020	+0.081
3	-2	23-104	3-19	0.181	0.136	-0.045	-0.984
4	-2	13-93	1-8	0.123	0.111	-0.012	-0.104
5	-2	20-107	8-28	0.157	0.222	0.065	+2.330
6	-2	7-67	1-25	0.095	0.038	-0.056	-1.459
1	-1	96-219	6-10	0.305	0.375	0.070	+1.12
2	-1	42-92	1-3	0.313	0.250	-0.063	-0.254
3	-1	72-163	6-15	0.306	0.286	-0.021	-0.434
4	-1	23-109	2-7	0.174	0.222	0.048	+0.432
5	-1	35-94	10-15	0.271	0.400	0.129	+3.217
6	-1	22-73	6-24	0.232	0.200	-0.032	-0.947
1	Tied	288-416	12-20	0.409	0.375	-0.034	-1.090
2	Tied	29-41	0-2	0.414	0.000	-0.414	-0.829
3	Tied	138-228	6-15	0.377	0.286	-0.091	-1.918
4	Tied	54-94	6-13	0.365	0.312	-0.049	-0.932
5	Tied	42-114	12-16	0.269	0.429	0.159	+4.462
6	Tied	34-74	11-22	0.315	0.333	0.019	+0.611
1	+1	34-46	1-2	0.425	0.333	-0.092	-0.275
2	+1	16-20	0-0	0.444	0.000	-0.444	-0.000
3	+1	106-109	2-1	0.493	0.666	0.174	+0.521
4	+1	46-52	4-3	0.469	0.571	0.102	+0.714
5	+1	66-57	4-7	0.537	0.364	-0.173	-1.902
6	+1	58-60	9-11	0.492	0.450	-0.042	-0.831
1	+2	28-23	0-1	0.549	0.000	-0.549	-0.549
2	+2	10-7	0-0	0.588	0.000	-0.588	-0.000
3	+2	68-38	1-0	0.642	1.000	0.358	+0.358
4	+2	47-35	1-0	0.573	1.000	0.427	+0.427
5	+2	71-31	1-2	0.696	0.333	-0.363	-1.089
6	+2	54-38	6-2	0.587	0.750	0.163	+1.304

Phew! Sorry about that monstrosity. We can probably ignore the first 18 lines I guess. Frankly, when teams are behind by 5 runs in the 3rd inning, and are facing this situation, there is going to be a lot of losing regardless of what they do, and not many oIBB's are issued. It's in the middle of the table where it starts to get interesting.

In my previous study, the "-1" situation was the outlier. When down by a run, teams actually seemed to gain wins when IBBing the batter early. Here we see it broken down further. Recall that I am using a different (larger) sample size this time around, but the effect is still there. Almost all of the difference comes in the 5th inning, where teams won 10 of 25 games after issuing an IBB, which is more than 3 full wins better than the non-IBB sample. The rest of the "down by a run" scenarios more or less even out. Is this a sample size fluke, or something else I haven't considered?

Since nobody really enjoys looking at a 54-row table, let's do some grouping. I will group the six innings into three groups of 2. Let's also group the scores into: Tied, ahead by 1 or 2, and behind by 1 or 2.

Here are the Wins gained by IBB's in these situations:

Innings	Score Diff	IBB Gain
1-2	Behind by 1 or 2	+1.817
1-2	Tied	-1.919
1-2	Ahead by 1 or 2	-0.824
3-4	Behind by 1 or 2	-1.090
3-4	Tied	-2.850
3-4	Ahead by 1 or 2	+2.021
5-6	Behind by 1 or 2	+3.140
5-6	Tied	+5.073
5-6	Ahead by 1 or 2	-2.517

My findings seem to actually be in line with both MGL and Peter. MGL asserted that intentional walks in this situation was not a good idea, and my findings seems to show that to be mostly true. Peter's assertion was that the results were too small to say much, and, frankly, that seems to be true as well. However, look at with innings 5 and 6, with the team tied or behind by a run, a total of 8 wins were gained with intentional walks.

Indeed, in innings 5 and 6 with the score either tied or the pitching team behind by a run, teams who did not issue the walk went 160-529, for a .232 winning%, whereas teams that took the bat out of the hitter's hands in this situation went 48-130 for a .282 winning%, thus improving their win total fairly substantially. I find this pretty interesting. Innings 1-4 however, seem to be a fairly consistently against issuing the walk.

So, in summary, is it a good idea to walk the bases loaded when it's early in the game and a good hitter is at the plate and first base is open? I have no idea.

Here is the IBB_GAIN broken down by inning. Too lazy to make a fancy table like before so I'll just copy/paste from sql*plus...

    INNING SUM(IBB_GAIN)
---------- -------------
         5    10.2684563
         4    1.11693613
         1    .074129052
         2    -3.1787919
         6    -3.9504488
         3    -4.9123056