Keystone for the Cubs

Over the Memorial Day weekend, it was leaked that Alfonso Soriano had told Cubs manager Lou Piniella that he would be willing to play second base if it meant that Micah Hoffpauir could get more playing time.

So far for the Cubs, second base has been manned primarily by Mike Fontenot when he’s not playing third filling in for the injured Aramis Ramirez, and Aaron Miles. Essentially, if they made this sort of move, the Cubs would be saying that they are not happy with the offensive output of either of those two to date and are looking for ways to get more punch in the batting order. Is that reasonable?

First off, Mike Fontenot probably deserves the nominal starting job. He’s been hurt by a bad BABIP this season that seems mostly due to bad luck. Based on his core numbers, he seems likely to positively regress to somewhere above his 2007 numbers. ZiPS sees him at a .328 wOBA for the rest of the season. He also provides a glove worth about +5 runs a year at second.

If we consider that the base case, would the Cubs be better off shifting Alfonso Soriano to second base and Micah Hoffpauir to left field? Soriano is already in the everyday lineup, so all we have to do for him is compare the impact of his defensive shift. Based on prior UZRs, Soriano is about 20 runs less proficient at second base than in a corner outfield spot. He would gain 10 runs back in scarcity value, but that still leaves a net negative of 15 runs (factoring in Fontenot’s +5) and that’s assuming that Soriano hasn’t gotten any worse at second base in the 3+ years since he last played there regularly and that his hitting wouldn’t deteriorate playing a tougher position.

We do not have enough defensive sample for Hoffpauir to say anything about his defense, so assuming for now that he would be an average left fielder (the scanty evidence we do have suggests he’s below average), Hoffpauir’s bat would have to be at least 15 runs (over a full season) more valuable than Fontenot’s in order for the net benefit to be positive. ZiPS sees Hoffpauir as worth a .357 wOBA the rest of the season. Over 600 PAs, the difference between a .357 wOBA and a .328 one is about 15 runs.

On a strict numbers basis, it looks like a neutral move for the Cubs, but that comes with a lot of assumptions about Hoffpauir’s defense and Soriano’s ability to transition back to second base. Even with those assumptions, the net gain for the Cubs only looks to be on the order of about nothing. Hardly seems worth the risk.