2010 Red Sox Projections - LF

This is post seven in a series of posts previewing the 2010 Red Sox.

2009 vs. 2010 Red Sox - LF:
2009 - Jason Bay
2010 - Jacoby Ellsbury

I understand that this is not how everyone would address this. After all, Ellsbury was a full-time outfielder for the Red Sox last year, and will be a full-time outfielder for the Red Sox this year. Nevertheless, I think that this the cleanest way to address this. The one concession I'll make is that I'm going to use the at-bats from CF last year, because Ellsbury led off in 2009 and will do so again in 2010.

Obviously, the loss of Jason Bay results in the loss of a significant amount of the 2009 team's power. Bay led the team in HR and RBI, and his SLG was second to Youkilis'. He was probably the second-best overall offensive player that Boston had in 2009, and they didn't replace him with a comparable offensi ve performer. What they've done is move Jacoby Ellsbury, last year's center fielder, over to left, and replaced Ellsbury in center with Mike Cameron. Neither Ellsbury, nor Cameron, is as good a hitter as Jason Bay, and there's no hiding or getting away from that fact.

What is also true, however, and vitally important in evaluating this year's team, is that both of those players are much better athletes, base-runners and defensive players than Bay. Some of what they gave up in power, they'll make up in other ways. And some, they won't. Bay certainly has flaws as a player, and I suspect that the Mets are going to regret that contract before it's done, but he was a very good hitter, and Fenway was a very good park for him. Losing him doesn't make the Sox better.

Jacoby Ellsbury may not ever be what some hoped he would be, but he apparently isn't going to be what some feared he'd be, either. After a struggle adjusting to big league pitchers, Ellsbury has shown some evidence of enough plate discipline to get his average and OBP up to productive levels. He probably won't ever hit 25 HR in a season, but I'd be willing to be that he gets to 15 in one of the next four years, and 20 isn't totally out of the question. He's a legitimately great base-stealer and an excellent base-runner. How good a center fielder he was is a matter for some debate, though the objective measurements don't like his 2009 season. Regardless, I can't imagine anyone making the case that he won't represent a significant defensive upgrade in LF over Jason Bay (about whose defensive abilities there is also some debate.)

FR had Jason Bay at 2 runs below average last year, UZR had him at 13 runs below average. UZR had Ellsbury at 9 runs above average for the 58 games in left in 2008, and FR had him well above average in left also. I think that it's very difficult to determine who much, exactly, their left field defense will improve this season, but I don't think that there's any question that it will be significantly better.

I've given Ellsbury 85% of the left-field at-bats (because I'm going to give him 10% of the center-field at-bats, too.) Jeremy Hermida picks up the rest.

Red Sox 2009 vs. 2010 - LF

Player	AB	Runs	Hits	2B	3B	HR	RBI	BB	IBB	HBP	K	SB	CS	SH	SF	GDP	BA	OBA	SPct	OPS	RC	RC/25
Jacoby Ellsbury (marcel)	575	91	169	25	7	10	58	47	2	6	80	52	9	4	5	10	.295	.352	.419	.772	91.1	5.24
Jeremy Hermida (marcel)	101	13	27	4	0	3	12	11	0	1	24	1	0	0	0	2	.269	.350	.434	.784	15.3	4.98
Jacoby Ellsbury (PECOTA)	575	100	169	33	7	9	59	49	2	6	75	51	10	4	5	10	.294	.353	.429	.783	92.7	5.30
Jeremy Hermida (PECOTA)	101	14	27	5	0	3	14	11	0	1	25	0	0	0	0	2	.269	.351	.453	.804	15.9	5.13
2009 LF	589	114	157	32	3	40	126	99	3	9	175	13	3	0	4	10	.267	.378	.535	.913	119.7	6.66
2010 LF (marcel)	676	104	196	30	7	14	71	59	3	7	104	54	9	4	5	12	.291	.352	.422	.773	106.4	5.20
2010 LF (PECOTA)	676	114	196	38	8	13	73	61	3	7	101	52	11	4	5	12	.290	.353	.433	.786	108.6	5.28

The 12-15 difference in Runs Created here understates the loss, because the 2010 left-fielders are taking more at-bats to provide less production than the 2009 left fielder. The transition from Bay to Ellsbury probably costs the Red Sox 20 runs in left field. The big question is, how many runs does it save them? You could probably extrapolate the best and worst case numbers and make a case that you save as many on defense as you lose on offense, but I don't believe it. You're probably looking at a net 10-15 runs deficit, which works out to about a game or a game and a half. It's a downgrade, but not a catastrophic one.

2010 LF projection: Big offensive downgrade, significant but smaller defensive upgrade. Net downgrade



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