Jason Bay vs. Kirk Nieuwenhuis: The Defensive Comparison

By Matt Musico

As Jason Bay ramps up his rehab in Pittsburgh, most Mets fans are cringing at the thought of the left fielder making his return to the lineup within the coming weeks. Not only has he been a bust for the last two-plus years, it is clear that the offense and team as a whole has been more productive with Kirk Nieuwenhuis in the lineup. When looking at the numbers, it is clear that Captain Kirk (.277/.355/.387) has been more productive than Bay (.240/.316/.493), but what about that other part of the game…you know, the part that you use the glove for?

Today’s game seems to have way too much emphasis on scoring and hitting booming home runs. We’ve seen time and time again that

pitching, defense, and timely hitting helps propel a team towards being successful and winning championships. So, with Bay’s return imminent, I decided to break down the defensive impact between him and Nieuwenhuis; who is worth putting out in left field most nights, to field the position? Instead of solely looking at errors and fielding percentage, I wanted to dig a little deeper to find statistics that can tell more of the story for a player’s defensive worth.

First, before we throw up the comparison, it’s probably best to get some of the defensive statistics lingo defined and out of the way. There were three main metrics that I looked at between these two outfielders to find their value to the Mets, and they include: Rtot/yr, Rdrs/yr, and RF/9. So, what the heck do those things mean?

Rtot/yr stands for Total Fielding Runs Above Average and measures a player by finding out the number of runs above or below average a fielder is worth. This calculation is based on 1,200 innings played, which equals about 135 games. Rdrs/yr stands for Defensive Runs Saved, which basically means how many runs a player saves his team in a given year; this is also based off of 1,200 innings played. RF/9 stands for Range Factor per 9 innings played, and is calculated by adding a defenders putouts and assists together, then dividing them by innings played. When looking at these statistics, keep in mind that the league average for fielding percentage is .980, and the league average for RF/9 is 2.09.


Jason Bay

Kirk Nieuwenhuis

Innings Played



Fielding %
























Now, it’s obvious that Nieuwenhuis has had many more chances to show his defensive worth than Bay has, but this is still pretty shocking. The most drastic piece of this analysis lays on the bottom of the table. Even though Bay beats out Captain Kirk in the Range Factor department, both players are above the 2.09 league average. Despite having better range, Nieuwenhuis has the clear advantage when it comes to saving runs for New York. Even if you look back to last season, Bay’s Rdrs/year was -3 and he has not once had a positive Rtot/yr as a member of the Mets.

Pitching and defense wins championships, huh? Well, with a pitching staff that is shaky (and I’m being really nice) once the ball is handed off to the bullpen, defense becomes even more important than it was in the beginning of the game. It’s evident that the bullpen needs all the help they can get; if blowing nine saves in 21 opportunities doesn’t scream help, I don’t know what will. So, strictly looking at the defensive statistics and not paying attention to the name attached to these statistics, who would you rather have in the outfield? I’d want the defender that will give me a Rtot/yr in the black and not cost me 20 runs a year. You combine that with Nieuwenhuis’ offense, and it should be a no brainer. Right?