Another datapoint in the "protection" discussion

One of the pieces of baseball conventional wisdom that sabermetricians have questioned is the idea of "protection." Protection says that a hitter gets a lot better pitches to hit, and will produce better numbers, with a great hitter behind him. We've got another situation to look at, now, for more evidence on the subject.

The speculation started quickly as people once again ponder whether David Ortiz can hit without Manny "protecting" him. The conventional wisdom says that Ortiz' numbers will drop, and there are already articles tying Ortiz' weak performance the past few days with the loss of that "protection."

From Nick Cafardo in yesterday's Globe:

There's David Ortiz indicating - and he acknowledges it's very early - that he's already feeling the effect of Manny Ramírez not being in the lineup to protect him.

This morning on ESPN.com, from Rick Sutcliffe, we read that:

Ortiz benefited from having Ramirez behind him in the lineup; however, he also changed as a hitter when he came to Boston in 2003 and stopped swinging at the fastball off the inside half of the plate. And with Ramirez hitting behind him, he saw a lot more strikes. Ortiz isn't close to 100 percent right now, but once he's completely healthy, teams aren't going to let Ortiz beat them. He's 2-for-20 with two RBIs in the five games since Ramirez was dealt.

Here's the thing - sometimes, we can actually objectively evaluate situations. These last four days are not the first four days that Ortiz has been in the Red Sox lineup without Manny. We actually have a track record, a history that we can examine. And thanks to David Pinto's invaluable Day by Day database, it's fairly easy to do.

So, here are the records for David Ortiz in a Boston uniform (including the five since the trade.) One set of numbers shows Ortiz' stats for games in which Manny started. The other set shows Ortiz' stats for games in which Manny did not start. (This is not a perfect set - there was a time early in their careers together when Ortiz hit behind Manny, but most of the games without Manny are from '06 and '07, when Manny was the cleanup hitter. There are some Ortiz at-bats in the "with Manny" category where Manny had left the game due to injury or score, and there are probably a couple of Ortiz at-bats in the "without Manny" where Manny was in the on-deck circle as a pinch hitter. But it should be representative.) And this is what the data shows:

David Ortiz in Boston

	G	AVG	OBP	SLG	OPS	AB/HR	IBB %	AB/BB
With Manny	677	.296	.390	.598	.988	13.544	12.44%	6.441
Without Manny	101	.306	.453	.611	1.065	12.963	15.96%	3.723

As expected, Manny's absence has led to more walks for Ortiz, some increase in intentional walks, and probably a fairly large increase in "unintentional intentional" walks. But his batting average and isolated slugging are higher without Manny, too. On the whole, he's put up a much better statistical performance without Manny in the lineup. Some of that is obviously a result of the additional walks, and some, if not most, of the additional walks are almost certainly a result of not having a Hall-of-Fame slugger in the on deck circle. But even without the walks, his performance on at-bats when not walking is better - higher average, more power, HR more frequently - without Manny in the lineup. The evidence is pretty overwhelming that, despite the early concerns in the press, David Ortiz' performance is not dependent upon having Manny Ramirez hitting behind him.