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Zobrist vs Fielder: A Position Adjustment Primer

Posted By Dave Cameron On August 8, 2011 @ 6:48 am In Daily Graphings | 226 Comments

Yesterday on Twitter, Buster Olney had some thoughts on WAR, and specifically, the way it values middle-of-the-diamond players compared to first basemen. A few selections from his comments:

#1: “Love advanced metrics,but anybody find something a little skewed to 2B/SS/CF? Ben Zobrist No. 6 overall, ahead of all first basemen, McCann?”

#2: “Zobrist, Victorino, Howie Kendrick and Yunel Escobar all ahead of Prince Fielder in WAR. You do wonder if positional adjustments too steep.”

#3: “If you asked 30 GMs who they would pay the most among these players–Victorino, Yunel, Kendrick, Fielder–off ’11 stats,30 would say Fielder.”

There were a few others sprinkled in there as well, but you get the general point. The common wisdom in baseball has been that run producers are the most valuable players in the game, and since WAR does not line up with that assessment, Buster is questioning whether WAR is wrong.

This is an understandable concern to some degree. When a new metric comes along, there is a legitimate “smell test” that it should pass. If we developed a metric to measure speed that called Bengie Molina the fastest guy in the sport over the last 10 years, you could justifiably assume that we made a big error somewhere. There is a place for logic and reason in testing the validity of calculations. But if all new metrics are forced to line up with preconceived notions of what’s true, they lose all value as well – we should not be willing to believe that what we currently hold true is infallible. The smell test needs to be balanced with an openness to the possibility that the metric is offering new information that we can learn from.

I believe Buster has that openness, for what it’s worth. He wouldn’t even be looking at WAR if he thought it was a junk stat created by nerds in their mother’s basement, so there’s no reason for mocking here. When people have legitimate questions about our metrics, we want to answer them. So, I thought it’d be useful to explain just why WAR likes Ben Zobrist so much more than Prince Fielder, and why that’s not wrong.

Let’s start with what makes a player valuable to begin with – production relative to their peers. A team gets a competitive advantage by having a guy who is better than what their opponents have at the same position, since every team has to field nine guys at the same nine spots. You can’t load up on shortstops or first basemen and have a team full of them, after all – you need a guy at each spot on the field.

Fielder is certainly a great hitter, but there are a lot of great hitting first basemen. He plays the same position as Albert Pujols, Joey Votto, Adrian Gonzalez, Miguel Cabrera, and Mark Teixeira, among others. Just those seven are all considered elite, franchise cornerstone type players, but the fact that there are seven guys at that level at the same position should tell you something about the scarcity of that kind of player. 23 percent of all teams in baseball have a first baseman who could easily be considered one of the best players in the game, and is paid as such.

Even the second tier of first baseman are pretty darn good hitters. We haven’t mentioned the likes of Paul Konerko or Ryan Howard, who routinely get MVP votes and are lauded as two of the games premier run producers. At first base, though, they can’t even crack the top rung. The bar is just set so high.

In 2011, the average line produced by all first baseman is .270/.344/.449, good for a .793 OPS. Right Field has a .775 OPS as a group, and then no other position is over .747. First base is the land of run producing sluggers, and it essentially takes an .800 OPS or better to be an above average hitter for the position. In fact, there are exactly 15 guys at the position with an OPS of .800 or better in 300 or more plate appearances this year.

Prince Fielder’s .991 OPS is obviously terrific, and is actually the best at the position this year, slightly edging out Miguel Cabrera for the top spot so far. It’s almost exactly 200 points better than the league average mark for a first baseman. He’s having a great year, no doubt.

Now, though, let’s look at Zobrist. He’s posting an .861 OPS, 130 points lower than Fielder, so you can see where there’s skepticism that the gap could be made up in other areas. But when you compare Zobrist to the baseline of all second baseman, the gap gets much smaller. The average Major League 2B is hitting .258/.318/.383 on the season, good for a .702 OPS. Zobrist’s mark is 159 points better than average for his position, and like Fielder, his mark is elite for his spot – only Dustin Pedroia (.880) has a better OPS so far this year. In fact, there are only five second baseman with an .800 OPS or better this year (again, 300 PA minimum), and the 15th best hitting second baseman in baseball this year is Alexi Casilla. The bar here is clearly not as high.

A 40 point gap of OPS relative to position average might still seem like a pretty decent difference, but it sounds bigger than it actually is. Fielder has produced 39 runs above an average hitter this year, while Zobrist has produced 24. The 130 point OPS gap is essentially equal to 15 runs, and once you adjust for just the 40 point difference relative to position, the gap closes to just seven runs. It’s certainly an advantage for Fielder, but it’s also the only advantage he has on Zobrist anywhere on the field.

For all of Prince’s exploits at the plate, that’s the only place he produces value. You don’t have to believe in advanced metrics to agree that Fielder is a below average defender at first base and a below average baserunner. By the metrics we use, Fielder is eight runs below average in those two areas put together, so he gives back half of his total (non-position adjusted) offensive advantage by not adding value there.

Zobrist, on the other hand, is an excellent defensive second baseman and a terrific baserunner, and we’ve got him at 11.5 runs better than average between those two aspects of the game. While he doesn’t have Fielder’s power, he is much faster and more athletic, and is able to use those skills to more than close the gap once defense and base running are factored in to the overall package.

By solely focusing on offensive metrics – especially things like HRs and RBIs, which are heavily skewed toward power hitting first baseman – and not looking at the position averages at each position, the sport has had a long history of overvaluing Prince Fielder’s specific player type. The Ryan Howard extension is a perfect example – he’s something pretty close to a league average first baseman, but he’s getting paid like a superstar.

Teams, however, have begun to learn from their mistakes. Look at the relative salary difference that guys like Carl Crawford and Jayson Werth commanded last winter, compared to a bat-only guy like Adam Dunn. By nearly any measure you want to use, Dunn was the superior hitter (until this year, anyway), but he got nearly $100 million less than Crawford because teams realized there was more to the the game than standing at the plate and swinging for the fences.

To Buster’s final point, he’s almost certainly correct that 30 out of 30 MLB teams would take Fielder over Zobrist going forward if the money was equal. But that’s essentially accusing WAR of saying something that it does not attempt to say. Single-season WAR is not, and has never been presented as, a true talent evaluator. It is a measure of past production over a certain time frame, but no one would argue that you should use four months of WAR data to say that one really good player is definitively better going forward than another really good player.

For the kind of which-player-would-a-GM-rather-have question that Buster is posing, we would certainly look at multiple years of data, aging curves, and expected regression in coming up with a projection of future value. We would not suggest that anyone look at 2011 WAR as a definitive ordered list of who the best players in the game are at this time – it’s not even trying to make that claim. It’s talking about past performance only, not what we expect going forward.

In fact, Buster’s criticism of WAR could be applied to any stat you want, traditional or advanced. If you interpret it literally, ERA currently says that Ryan Vogelsong is the best pitcher in the National League. That’s crazy, of course, but no one interprets single-season ERA that way. Single season batting average gives you Casey Kotchman as the third best hitter in baseball. It’s not just the advanced stats that produce results that “don’t pass the smell test”.

I get where Buster’s confusion is coming from. For years, we’ve been told that power hitting first baseman are the creme de la creme of baseball players. WAR does not agree with that assessment, and it challenges long-held beliefs about how players have been valued. But that does not make it wrong by default. Challenging assumptions is something any good metric should do, and the fact that it’s shining a light on previously underrated stars like Zobrist is one of the reasons why WAR is so valuable to begin with.


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