The halfway point of the season passed about a week ago, but the next three days represent the observed mid-point in the season. Absent meaningful baseball games to discuss, we’re left with a short period of evaluation. We do this every year, and we try to take it from a different angle each time. This year we’ll look around the roster and compare the Yankees to their positional peers. We start today with the infielders.

To keep things on a similar scale, we’ll measure everything in runs. On offense this will be FanGraphs’ Batting Runs Above Average (the offense component of WAR, which is wOBA park- and league-adjusted) and UZR. Since UZR has its share of issues, we’ll also add Baseball Prospectus’s Fielding Runs Above Average for more context — though there is no rank on FRAA.

1B, Mark Teixeira

(Charles Krupa/AP)

A notoriously slow starter, Teixeira helped eliminate that narrative when he homered in the seasons’s first three games, and four of the first five. It spurred his best April in recent memory: .256/.392/.549. He’s fallen off considerably since then, though, hitting .240/.338/.508 since May 1, for a collective first-half line of .244/.352/.519, or a .378 wOBA.

Offense: 18.0, 6th. I actually expected Teixeira to finish a bit worse here, on account of the insane production among first basemen this year. Sixth isn’t bad, but the players ahead of him are way ahead of him: Paul Konerko, who ranks fifth, is nearly seven runs better than Teixeira at the plate.

Defense: 2.9, 7th. UZR has rarely worked out favorably for Teixeira. We see him make amazing plays every week at first, yet he has two years of below-average UZR numbers as a Yankee. I’m not sure why, but the answer might simply be that the numbers that feed into UZR don’t necessarily reflect the skills that make a first baseman valuable. Or maybe it’s seeing something that our eyes aren’t. FRAA has him at -2.9 runs.

WAR: 3.1, 5th. Teixeira leapfrogs Konerko here not just because of defense, but because Konerko has a league-worst -7.3 base running mark. Yes, that’s worse than Posada.

2B, Robinson Cano

(AP Photo/Kathy Willens)

After a career year in 2010, Cano had set the bar high for 2011. He hasn’t quite reached that level of production, but he has surged at times. He ended the first half with a .296/.342/.521 line that looks good, not great, but is actually relatively elite given the offensive environment.

Offense: 15.8, 5th. Would you believe that Dustin Pedroia is first among 2B with 18.1 runs above average? He’s a little ways ahead of Cano thanks to his much higher OBP. Cano has the power game going on, which keeps him right around the leaders. He’s actually closer to first than his is sixth, so he’s grouped in with Pedroia, Rickie Weeks, Ian Kinsler, and Ben Zobrist as the top-tier offensive second basemen in the league. You can throw Howie Kendrick, at 13.1 runs above average, in there if you want as well.

Defense: -2.5, 16th. As has been the norm. UZR rates Cano lower than what we observe from day-to-day. This year he’s been observably worse than he was in 2010, but it still doesn’t feel as though he’s a below average defender. Unsurprisingly, FRAA has him at 1.2 runs above average. Then again, it had him slightly below average last year, and well above average every other year of his career, and had 2008 as his best year.

WAR: 2.9, 8th. This is where his fielding numbers hurt a bit. It’s tough to imagine that Brandon Phillips is more than a win better than him in the field, but that’s where UZR is going with this season. It might not be completely accurate, since batted ball data isn’t perfect and can affect UZR. But it might just be the effects of a small sample: half a season of UZR is akin to a month or so of offensive data, and so it could be the result of a simple slump.

3B, Alex Rodriguez

(Kathy Willens/AP)

After he got off to an incredibly hot start, Alex battled injuries, first to his oblique and then to his knee, throughout the first half. He ends it on a downer, as surgery will cost him four to six weeks. But given how well he hit even with the injuries, a healthy, rejuvenated Alex could be an enormous threat down the stretch.

Offense: 15.1, 2nd. Kevin Youkilis has greatly outhit every third baseman in the league, as he’s 6.8 runs ahead of Alex. That’s to the Sox advantage in one way, since they essentially have two guys who hit like first basemen. But as you’ll see in the next few categories, it’s not all hunky dory.

Defense: 10.3, 1st. There is no doubt that Alex has played a superb third base this season. He looks smoother out there in the field, which likely has to do with his trimming down this winter. But has he provided a win above average with his glove? Just as we should be skeptical of Cano’s low UZR, we should be skeptical of Alex’s high one. He’s been good, but I’m not so certain he’s been that good. Then again, FRAA has him at 6.2 runs above average, which is already better than any of his years at third except for 2008.

WAR: 4.0, 1st. This is largely a fielding-based advantage, but it does appear that A-Rod is that much better than Youkilis with the glove at third. Third base is a pretty bleak position this year, and so having Alex has been a great advantage. That stinks, because he’s going to miss plenty of time. But it also means that Eduardo Nunez shouldn’t have much trouble hitting like an above-average third baseman.

SS, Derek Jeter

(Kathy Kmonicek/AP)

Jeter was primed for a bounce back. He had worked all winter trying to simplify his swing, removing a hitch that hurt him greatly in 2010. Yet it didn’t work out at all. He abandoned his new mechanics shortly after the season started, and at the break he’s more or less at the same level as last year. Missing time with a calf injury didn’t help matters. Unless Saturday was a portend for the second half, it appears that we’ll have a second half of Jeter atop the lineup with a .330ish OBP.

Offense: -2.3, 15th. There is Jose Reyes, and then there is a second tier of very good offensive shortstops: Asdrubal Cabrera, Jhonny Peralta, and Yunel Escobar. It starts to dip a bit after that, with a cluster around 5 runs above average, until we get into the negatives. Unfortunatley, Jeter doesn’t even fall into that 5-run group. He has been the offensive equivalent of Ryan Theriot, which is something I never thought I’d have to type.

Defense: -1.0, 15th. Again, the eye test pretty much lines up with the UZR assessment. Jeter hasn’t been great in the field, but he’s certainly looked better than he did last year. It’s clear that he put more emphasis on his defensive game during the off-season, because he’s getting to more balls to his left. Maybe it’s a positioning thing, too. FRAA has him at -3.7, which, while not very good, is way, way, way, way better than the numbers throughout his career on that scale.

WAR: 0.9, 17th. In one way, the injury hurt him here, since WAR is a counting stat. In another way, since he’s below average both at the plate and in the field, perhaps his DL hint merely stanched the bleeding. In any case, he stands further below his peers than any other Yankees starter. That’s something that absolutely needs to change in the second half, especially with A-Rod — who is so far ahead of his peers — missing time.

Russell Martin, C

(AP Photo/Charlie Neibergall)

Martin started off the season with a bang — thanks, Ned! — but has dropped off considerably since then. He ended the first month at .293/.376/.587, but has hit just .185/.299/.287 since then. He seems like a guy who would benefit greatly from the three days off. Of course, he’s the backup catcher for the AL in the All-Star game, which means he’ll play.

Offense: 1.0, 13th. Part of this is the time he missed, and part of it is the horrible performance since the end of April. Injury might have explained some of his poor performances, but his numbers have continued to decline even after he recovered.

Defense: 0.5, 6th. I’m honestly not sure how they’re doing defense, since there is no UZR for catchers. Normally they use Defensive Runs Saved, but those are in whole numbers, not fractions. In any case, Martin grades out at around the same level as his peers, which passes the eye test. His pitchers, with their long deliveries, might be hurting his caught stealing numbers, too.

WAR: 1.7, 8th. Considering his offensive shortcomings, this isn’t too bad. He might be even better, too, since Carlos Santana has logged about a third of his playing time at first base. There’s clear room for improvement, too, which could bode well for Martin in the second half.