I’ve been playing around lately with some graphs depicting what a player contributes — offense, defense, and both combined with a positional adjustment — versus the theoretical replacement level. It’s a pretty quick way to see the peaks and valley’s of a players last few years. Aaron Rowand might want to forget his first season with the San Francisco Giants in a 5-year contract. Rowand, who had a career year in 2007 with the Philadelphia Phillies*, entered San Francisco with talks of leadership, GAMER-tude, and hopefully the skills to play an above-average center field.

*Quick side note: Using FanGraph’s new handy-dandy Win Value Leaderboards, we can see just how good Rowand was in 2007. In ’07 he hit: .309/.374/.515 and played above-average defense in CF with a bUZR of +8 runs. Add all that up, and Rowand was worth +5.9 wins above replacement in the National League for his solid season. A 5-6 win player is a legitimate star in any lineup and Rowand’s 5-win total placed him, in terms of value, between Grady Sizemore and Aramis Ramirez. He was the 16th most valuable position player in baseball. By all accounts, Rowand’s year was amazing, the Giants player evaluation skills? That’s still to be determined.

In short, Rowand had a tough first season with his new club. He started the year on a BABIP-fueled tear, but in the 2nd half of the season, his BABIP returned to Earth and he crawled to the finish line. His 2nd half line of: .242/.309/.356 tells a scary story that haunts more than just a few Giants fans. I’ve written gobs about Rowand on this site, so I won’t rehash his ’08 season in it’s entirety. If you’re interested in that, just run a search for ‘Aaron Rowand’ or click on the Aaron Rowand ‘tag’ in the bottom of this post to find more articles on him.

What I do want to look at in today’s post is a graph of Rowand from 2002-08. As I mentioned above, I’ve graphed offense, defense, and both combined with an adjustment against the replacement level. A few quick words on my methods.

1. For offensive batting runs, I’m going simple and using FanGraph’s wRAA. It’s park adjusted — which should help us some with Rowand coming from two great hitters parks in Chicago and Philly — and it’s quickly and easily available from FanGraphs.

2. Again, utilizing FG, I’ll be using bUZR for my defensive metric. UZR is just about the best defensive metric out there and FanGraphs has done a great job making it freely available and easy to parse.

3. Everything is pro-rated to 700 PA’s in order to make things easy to read.

4. OPD = wRAA + bUZR + Positional Adjustment for playing CF.

5. I’ve adjusted the defensive positional adjustment for Rowand from 2002-2004. In those seasons he logged up to 100 innings in the corners and I’ve accounted for that. What I didn’t do was adjust the defensive replacement level line. It’s still set for CF. The adjustments from ’02-’04 are very small and only swing his run total by a fraction.

6. Replacement level is set to 2.25 wins or 22.5 runs. Replacement has varied a little since 2002, but it’s a quick-and-dirty measurement and for this graph, it serves it’s purpose well enough.

7. Thanks to Sky Kalkman of Beyond the Box Score for helping me clean up my spreadsheet that I’m using today.

Let’s check the graph and see what parts of Rowand’s game — offense or defense — have been changing in the past seven years.

Click to enlarge

Let’s examine Rowand’s bat. The orange-slashed-line is for his wRAA pro-rated to 700 PA’s. Rowand’s bat has tended to go up and down every couple of years. Starting from 2002, he’s had OPS+’s of: 81, 102, 130, 93, 86, 123, and 94. 2004 and 2007 were definitely peak years for Rowand at the dish, but most of the time, his bat has played much closer to ‘average’ — or a score of 0 runs — than way above. And, in both ’04 and ’07, Rowand had excellent BABIP’s of .341 and .348. Hitters tend to have more influence on their BABIP’s, his career BABIP is above-average at .325. I found it interesting that Rowand’s BABIP in 2008 was .332, still above-average but much of it was pumped up by his April and May BABIP’s of .413 (!) and .377. Outside of July, Rowand had a BABIP of sub-.300 in each month of ’08. It appears that if Rowand can hit a .340+ BABIP, he’s an impact bat, and if not, he’s closer to an average hitter, which has value.

Outside of his peek years, Rowand’s 2008 performace at the dish wasn’t totally out of place, the most concerning problem may have been his defense. Defense is noted by the green-slashed-line and you can see that while Rowand’s bat has gone up and down over the last few years, he’s been a pretty steady defender. That is, until 2008 when he saw a siginifact drop in his performance. Pro-rated to 700 PA’s, Rowand’s defense in CF has tended to play around +10 runs, that’s about +1 win and it’s fantastic defense to be getting in center. The problem was that last season Rowand stopped defending and fell to around -12 runs on defense in center field. His range, a previous strength, looked very poor and his throwing arm — which bUZR doesn’t account for, but it matters a little — was very erratic. Did his rib injury affect him on defense that much? It’s possible. But, the Giants have to consider that with a player like Rowand — lots of wear and tear — he might start to age poorly as he enter’s his early-30′s. If his defensive decline was injury related, then he might have some bounce back in 2009. But, if it’s a sign of things to come, the Giants are going to have a problem. I think Rowand’s defense is truly one of the bigger wildcards for next season.

You can see from the OPD line, that Rowand has been an above-replacement level player. But, he was pretty close to the line last season. By our graph, it was his worst performance since 2002. In my latest WAR projections, I’ve got Rowand playing +2 wins — or about +20 runs in our graphs context — above replacement level. Much of that depends on him returning to an average defender in CF — I’ve got him right at +0 runs defensively — and maintaining the ability to be a league average hitter. I’m not freaking out about Rowand just yet, but it wasn’t the best way to start a 5-year contract.

Comment Starter: Yes or No, Rowand will bounce back in 2009.