Analyzing the Neil Walker for Jon Niese Trade

Perhaps lost in the shuffle of some other big name baseball transactions this week was the trade between the Mets and Pirates earlier this week.

Pittsburgh sent second basemen Neil Walker to New York in exchange for lefty starter Jonathon Niese.

The move fills an obvious need for the Mets, who had a hole at second base after the team let postseason hero/average baseball player Daniel Murphy walk, and Ben Zobrist signed with the Cubs.

The Pirates, meanwhile, get backend of the rotation depth and another chance to work their magic on a pitcher who had struggled in the previous season with another team (see J.A. Happ, Francisco Liriano, and A.J. Burnett ).

Walker to the Mets

Like Murphy, the 30-year-old Walker is a bat-first second baseman with good power for someone at his position.

He has a .272/.338/.431 slash line (114 wRC+) in 3,426 big league plate appearances. He had a down year by his standards last year (108 wRC+) but had a career year in 2014, when he slashed .271/.342/.467.

His career offensive numbers are not all that different from Murphy’s (.288/.331/.424, 109 wRC+), but Walker does not give up nearly as much value with his glove.

Walker has been about 10 runs below average at second base in six seasons in terms of Defensive Runs Saved (DRS), which averages out to about -1 run per 1,200 innings.

Murphy, meanwhile, has been 42 runs below average in five seasons at second base, averaging -11 DRS per 1,200 innings.

The difference in the field explains why Walker has been a career 16.4 rWAR player, while Murphy has been worth 12.5 rWAR (in terms of rWAR per 650 plate appearances, Walker has averaged 3.6, compared to 2.8 for Murphy).

The difference is less stark over at FanGraphs, which uses Ultimate Zone Rating to measure defense, where Walker has been a 15.4 fWAR player, while Murphy has been worth 13.8 fWAR (UZR rates Murphy better and Walker worse than DRS does).

In terms of the player they gave up, Niese was ultimately a spare part, as the Mets have an abundance of pitching depth, featuring Matt Harvey, Noah Syndergaard, Jacob deGrom, Steven Matz, and Zack Wheeler.

The news could also open up the door for Bartolo Colon's return to New York, which is a win for baseball fans everywhere.

Niese to Pittsburgh

Can Niese be the Pirates’ latest reclamation project?

It’s certainly possible, given that Niese has been a slightly above average pitcher until struggling last season.

His unadjusted career numbers seem good, given his 3.91 ERA, 3.84 FIP, and 3.74 xFIP. We need to adjust, though, for the fact that his home park has been pitcher-friendly Citi Field, and once we do, we arrive at a 106 ERA-, 100 FIP-, and 97 xFIP-.

These are still fine numbers for a number-five starter.

Things will be less fine for the Pirates if he duplicates his 2015 season, which saw him post a 112 ERA-, 114 FIP-, and 106 xFIP-, as well as a 121 cFIP and 128 DRA-, per Baseball Prospectus (100 is average for these stats).

His strikeout rate dipped to a career-low 14.7%, while his 7.7% walk rate was his second highest since 2010.

The deal clearly seems to be a good one for the Mets, who will continue to have above-average offense at second base without sacrificing nearly as much on defense.

For Pittsburgh, there are more variables to the equation, including who plays second base in 2016 (Josh Harrison seems to be the answer).

As for the players the Pirates received in the trade, provided 2015 was a fluke and not the beginning of a decline, they’ll have a roughly-league average pitcher at the back of the rotation.

We’ll find out in a few months.