2013 Preseason Prediction #9 – Jhonny Peralta

This would be a good time to show the differences between Baseball Reference and FanGraphs as far as batted ball data is concerned. Both sites get their information from different sources (Baseball Reference from Retrosheet and FanGraphs from Baseball Info Solutions) and so there are some differences in how they categorize line drives, ground balls and fly balls. Normally it's small enough that the same conclusions can be drawn regardless of which site is used.

Using Jhonny Peralta as an example:

2010	GB	FB	LD	Total Batted Ball
FanGraphs	157	199	102	458
Baseball Reference	158	192	107	457

The difference in ground balls was 1, the difference in fly balls was 7 and the difference in line drives was 5. There is a difference in total batted balls because Baseball Reference classified one of the batted balls as a bunt.

2011	GB	FB	LD	Total Batted Ball
FanGraphs	157	194	88	439
Baseball Reference	161	195	83	439

Again, there's not much difference; 4 in ground balls, 1 in fly balls and 5 in line drives.

2012	GB	FB	LD	Total Batted Ball
FanGraphs	177	157	94	428
Baseball Reference	182	171	75	428

Now there's a noticeable difference. While the difference in ground balls is only 5, fly balls have a difference of 14 and line drives have a difference of 19.

This is a big difference since FanGraphs says Peralta had a 22.0% line drive rate (94/428) but Baseball Reference says Peralta had a 17.5% line drive rate (75/428). A very simple xBABIP formula is to add .120 to the line drive rate. It's a very quick "luck" formula for someone who doesn't want to do a lot of work. Peralta had a .275 BABIP in 2012 and using FanGraphs' LD rate would give him an xBABIP of .340. Using Baseball Reference's LD rate would give Peralta an xBABIP of .295. One shows that Peralta was very unlucky while the other shows that he was only slightly unlucky.

		FanGraphs		Baseball Reference
	BABIP	LD	xBABIP	LD	xBABIP
2010	0.275	22.3%	0.343	23.4%	0.354
2011	0.325	20.0%	0.320	18.9%	0.309
2012	0.275	22.0%	0.340	17.5%	0.295
Career	0.310	20.3%	0.323	19.1%	0.311

According to these numbers, it looks like 2011 was similar to his career average and thus that is his true talent level. However, it's always good to look at the most recent seasons for future performance. 2012 and 2010 look very similar (more so just looking at FanGraphs) and therefore 2011 would be the outlier. Peralta could just be an exception and he'll look like he's underperforming his batted ball data, since he's now done it twice in his most recent 3 seasons when really that's just his true talent level. So now the question is, will Peralta have a season like his 2011 and career, or will it be more like 2010 and 2012? And which one was a better representation of what happened in 2012, FanGraphs or Baseball Reference?

I'm going to say Peralta's most recent seasons overrule career. It's always better to be conservative with predictions anyway.

Experts' Predictions/Projections:

	AB	AVG	OBP	SLG	HR	RBI	SB	BB	K
Steamer	436	0.258	0.321	0.410	12	57	1	40	83
Oliver	518	0.253	0.316	0.407	16	68	2	47	102
ZiPS	531	0.258	0.318	0.395	14	71	1	45	103
Bill James	530	0.264	0.329	0.423	16	74	1	49	108
RotoChamp	520	0.267	0.330	0.415	14	69	1	47	102
CBS Sports	540	0.252	0.312	0.398	14	68	0	47	108
ESPN	535	0.264	0.323	0.426	17	78	1	48	100
MLB.com	543	0.260	0.322	0.427	18	69	1	-	-
FanGraphs' Fans (20)	527	0.256	0.308	0.400	14	66	0	41	106

Update: 4/1

My Prediction:

	AB	AVG	OBP	SLG	HR	RBI	SB	BB	K
2012 Prediction	539	0.278	0.335	0.456	22	84	0	48	100
2012 Actual	531	0.239	0.305	0.384	13	63	1	49	105
2013 Prediction	526	0.241	0.305	0.380	13	66	1	48	105

Fantasy Impact: Unless you're in a deep league or an AL Only league, Peralta probably should be a non-factor in the draft. If you missed out on a top shortstop, there are more intriguing ones than Peralta, including Josh Rutledge , Jean Segura and Andrelton Simmons .