Baseball Musings: Probabilistic Model of GDPs

March 25, 2007

Probabilistic Model of GDPs

A few days ago I introduced the idea of a probabilistic model of Ground into Double Plays (GDP). The probabilistic model of range just measures the ability to turn a ball into an out. For infielders, however, they're often asked to turn a ground ball into more than one out. The idea is to take a very specific situation; ground ball hit, man on first, less than two out and build a model that measures both plays made and GDP turned. With that model, we can ask which fielders perform well in that situation.

In building this model, I left parks out of the parameters. Basically, I thought the sample size would be too small if I left the parks in. This probably hurts the three teams that play of artifical turf.

Let's start by looking at the ability of shortstops to start a double play. The following table looks at three indexes for each fielder. The Plays Made (PM) index measures Plays Made / Predicted Plays Made. This measures the fielder's ability to turn a ball into an out. The GDP index does the same for ground double plays. Does the fielder start the expected number of double plays? And finally, an outs index that looks at the total number of outs accured to the fielder on these balls in play. It could be a fielder is making up for a lack of range by being really good at starting GDPs, or vice versa. Remember, this says nothing about the pivot man or the receiver at first base. In this context, we're only looking at the fielder who starts the play.

Probabilistic Model of GDPs, Ground Balls, Man on First, Less than Two Out, Shortstops Starting GDP (2006 Data Used to Build Model)
Player	Ground Balls In Play	Actual Plays Made	Predicted Plays Made	PM Index	Actual GDP	Predicted GDP	GDP Index	Actual Outs	Predicted Outs	Outs Index
Craig Counsell	183	40	32.14	124.44	32	21.23	150.72	72	53.38	134.89
Khalil Greene	219	53	45.27	117.08	31	28.68	108.07	84	73.95	113.59
Stephen Drew	121	26	23.68	109.82	17	14.29	118.92	43	37.97	113.25
Clint Barmes	283	56	53.75	104.18	42	33.03	127.16	98	86.78	112.92
Juan Uribe	274	58	50.75	114.29	34	31.85	106.75	92	82.60	111.38
Hanley Ramirez	352	71	67.58	105.05	49	43.18	113.48	120	110.76	108.34
Miguel Tejada	342	76	72.84	104.33	52	45.35	114.66	128	118.20	108.30
David Eckstein	298	61	56.74	107.50	38	34.92	108.81	99	91.67	108.00
Jack Wilson	290	64	62.47	102.45	46	39.39	116.77	110	101.86	107.99
Rafael Furcal	396	92	85.54	107.55	58	55.24	104.99	150	140.78	106.55
Bill Hall	228	55	50.83	108.21	33	32.90	100.30	88	83.73	105.10
Bobby Crosby	237	44	42.12	104.47	29	27.37	105.94	73	69.49	105.05
Alex Gonzalez	244	50	51.18	97.69	38	33.41	113.74	88	84.59	104.03
Jimmy Rollins	333	70	69.50	100.72	48	44.05	108.97	118	113.54	103.92
Carlos Guillen	303	65	64.24	101.18	45	41.63	108.10	110	105.87	103.90
Adam Everett	309	66	63.51	103.91	41	40.15	102.11	107	103.67	103.22
Ronny Cedeno	240	49	46.28	105.87	28	29.54	94.79	77	75.82	101.55
Michael Young	410	88	86.89	101.28	54	55.41	97.46	142	142.30	99.79
Jason A Bartlett	214	50	47.40	105.49	28	31.86	87.90	78	79.25	98.42
Jose Reyes	304	67	66.70	100.45	40	43.66	91.62	107	110.36	96.96
Omar Vizquel	297	64	65.48	97.73	42	44.00	95.45	106	109.49	96.82
John McDonald	170	25	26.52	94.26	18	17.91	100.50	43	44.43	96.77
Orlando Cabrera	319	58	60.40	96.03	38	39.02	97.38	96	99.42	96.56
Felipe Lopez	319	67	64.47	103.93	34	40.58	83.78	101	105.05	96.15
Angel Berroa	337	69	72.29	95.44	46	47.91	96.02	115	120.20	95.67
Jhonny Peralta	357	82	84.45	97.10	50	55.63	89.88	132	140.08	94.23
Alex Cora	127	30	32.94	91.07	21	22.16	94.76	51	55.10	92.56
Marco Scutaro	146	34	37.58	90.47	24	25.22	95.15	58	62.81	92.35
Edgar Renteria	347	63	67.67	93.10	39	43.19	90.30	102	110.86	92.01
Yuniesky Betancourt	350	60	66.40	90.36	43	46.02	93.44	103	112.42	91.62
Julio Lugo	182	32	35.29	90.68	21	23.66	88.74	53	58.95	89.90
Ben T Zobrist	131	25	28.09	89.00	17	18.93	89.82	42	47.02	89.33
Juan Castro	146	23	25.18	91.33	13	15.27	85.11	36	40.46	88.98
Derek Jeter	336	63	70.96	88.79	40	45.81	87.32	103	116.77	88.21
Royce Clayton	234	43	47.02	91.44	20	29.67	67.40	63	76.70	82.14
Aaron W Hill	108	16	20.33	78.70	7	12.82	54.62	23	33.14	69.39

Notice how few chances fielders get to turn GDPs. On the best teams, they get a little over two chances a game. Secondly, Arizona does a good job of picking out shortstops, as Counsell and Drew are near the top of the list. And if you don't like Derek Jeter, here's another area where you can pick on him.

The other thing that strikes me about the list is that shortstops who are good at making plays are also the ones good at starting double plays. Ronny Cedeno is unusual in that he's good at getting an out, but didn't do well starting DPs. Could it be that Todd Walker was just a poor pivot man? I hope further research using these models will help answer that question.

Posted by David Pinto at 11:46 AM | Defense • | Probabilistic Model of Range | TrackBack (0)

Comments

It's virtually useless without looking at the DP partner. Are Drew and Counsell really great, or is it that Orlando Hudson is so good on the receiving end. Interesting start to an idea, but that's all.

Posted by: Quorge Sand at March 25, 2007 02:39 PM

David, indeed an interesting start. It looks like your using BIS's vector data, so you've got a good data set from which to start. The problem I see here is that you're giving the SS credit for things that are out of his control. On a ground ball, the SS's job is to get to the ball (range), pick up the ball (hands), and throw it to the 2B covering the bag (arm). The rest is up to the 2B covering (to catch the throw, pivot, and throw to first) and 1B (catch the ball from 2B). You might counter that it's the SS's job to do all of his assignments *quickly*, so that the 2B and 1B can do their jobs. (That's going to be a function of how far away he has to range and how far of a throw he has to make, in addition to his range and arm skills.) You'd be right...

Then, there's the issue of runner speed and handedness. Try to make a good measure and all anyone tells you is what's wrong with it!

I didn't need another reason to hope Derek Jeter decides to join an international humanitarian aid organization (bad idea to wish harm on anyone) but thanks.

Posted by: Pizza Cutter at March 25, 2007 04:22 PM