Anchoring: A cognitive bias that describes the common human tendency to rely too heavily on the first piece of information offered when decision making.
I don’t understand the leadoff hitter, Denard Span. I think I have figured out what is going on, and it is an interesting psychological bias. Span one time played like a leadoff hitter, and was introduced to Nationals fans as a leadoff hitter. Even if evidence points another way, fans haven’t re-evaluated that assumption. I have always thought that the goal of the leadoff hitter is to get on base, run the bases, and score when the best hitters on the team get base hits with him in scoring position.
Getting on base: So far this year there are 35 players who have at least 50 at bats in the lead off position; Denard Span ranks 28th in OBP at .297. Virtually every team in baseball has a better leadoff man at getting on base than the Nationals. Last year, there were 17 players who had at least 400 at bats in the lead off position, Span ranked 15th in OBP at .322.
Base Running: So far this year Span has 4 stolen bases, which has him tied for 44th in baseball (in other words just a guy.) Last year he tied for 35th in stolen bases. He is a decent base stealer, but he isn’t a guy so fast and so dangerous on the bases that he causes havoc the way guys like Ellsbury, Rajai Davis, or Billy Hamilton do.
Base Stealing is fine, but there is more to base running than just swiping a bag. There is also the going first to third on a single and scoring on a double from 1st. These are the types of things that get overlooked sometimes, but help a team get the extra run. WAR’s base running component tries to tie all that together. Last year, Span ranked 66th in base running as judged by WAR. Ian Desmond and believe it or not Ryan Zimmerman scored as better on the base paths than him.
Scoring Runs: Span ranked 61st in runs scored last year with 610 at bats. Despite having the most at bats on the Nationals he was only 4th in scoring runs. Jayson Werth scored more runs in 150 fewer at bats because he was actually on base.
Just about any metric you use, Span isn’t particularly good at being a leadoff hitter currently. I think he is a pretty good Center Fielder and a good all around baseball player. He is actually one of my favorite players on the team. I actually own a #Spanning T-Shirt.
Why do the Nats, and in general the fan base, insist he is still a leadoff hitter? Much of that is because of his career stats. Span is a .350 OBP over his 6 seasons, but he is trending down. He career numbers are propped by his high walk rate his first few years in the league. Three of the last 4 years he hasn’t even had an OBP over .333, the level which I would consider the minimum expected of a leadoff hitter.
The answer to this question is partially in anchoring bias. The team and fans say Span is a leadoff hitter so we just assume he is. When he goes on a good run like he did in the second half of last season (when he had a .337 OBP) the team and fans say, “now he is playing like a leadoff hitter.” Some nights he goes 3-5 and hits a triple; most nights he doesn’t. When he doesn’t play like a leadoff hitter we just remember that for a short period of time he did.
In reality he doesn’t get on base enough or do the things good leadoff hitter do. He is a 3.5 WAR player that plays a meaningful roll anchoring the outfield on a pretty good team. Lets not pretend he is something he is not.