Mighty Joe Nelson

On Friday, the Florida Marlins non-tendered right-handed reliever Joe Nelson, officially allowing him to hit the open market. While the market for relief pitchers has not been as lucrative as the previous offseason, Nelson apparently has a wide array of suitors. In fact, according to one source, 19 teams are vying for the services of the newest reliever to become available. So, who is Joe Nelson, and why is he in such high demand?

Nelson turned 34 years old back in October and, prior to last season, had a whole 47.1 major league innings to his name. Two of those innings came in 2001, with the Braves. The next two and two-thirds did not occur until 2004, when he made three relatively ineffective outings with the Red Sox.

In 2006, however, the Royals gave him a legitimate shot out of their bullpen. While his overall numbers did not portend greatness by any stretch, a few signs pointing to potential success were evident. For starters, Nelson struck out 8.9 batters per nine innings, stranded runners at an above average rate of 72.7%, and held hitters to a .281 BABIP. His fastball averaged nothing more than 90 mph, though, and he appeared to complement that with a simply average changeup. All told, his 4.31 FIP deemed him a bit above replacement but by no means dominant.

Nelson did not pitch in 2007, but, after dominating for the Florida Marlins AAA affiliate in 2008, earned himself another call to the show. In the minors last season, Nelson fanned 12.6 batters per nine innings and limited his walks en route to a 6.0 K/BB. He posted an FIP of 1.72 and an ERA of 2.10, stranding 80% of his baserunners in the process.

On the big club, Nelson did not disappoint, as he pitched 54 very effective innings in 59 appearances. In those innings, Joe surrendered just 42 hits, issued no more than 22 walks, and struck out 60 batters. The rest of his numbers looked even better: a 1.19 WHIP, 10.0 K/9, 2.73 K/BB, 84.8% LOB. All told, Nelson posted a 3.45 FIP, which, while still very solid, ended up much higher than his 2.00 ERA.

He was not throwing harder in 2008 than 2006, and he did not implement any new pitches either. A major difference between the two seasons can be found in his rate of inducing swings on pitches out of the zone. Not only did he throw a lower percentage of pitches in the strike zone, but he increased his O-Swing% from 21% to 27%. On top of that, batters made contact just 50% of the time on these pitches, way down from the 59% rate against two years earlier.

Marcel projects Nelson for a 4.21 FIP in 52 innings of work next season. With so many suitors it is probably a good bet that his average leverage index of 1.16 last season will rise a bit. After all, 19 teams do not line up for a mop up man. Before factoring in the leverage index of his appearances, Nelson is about +3 runs above replacement. Multiply that by an LI in the vicinity of 1.20-1.45 and he could be worth anywhere from +3 to +6 runs above replacement. Assuming the going rate of $5 mil/win, Nelson, at fair market value, would sign for 1-yr/$2.5 mil, essentially the same contract recently inked by Chan Ho Park.

Given the likelihood of a plethora of teams vying for his services, a bidding war of sorts may ensue, which could theoretically bump his fee up into the $5 mil range. Pretty interesting given that he is 34, has struggled to stay around the big leagues, and realistically only put together one decent season. Nelson may be a valuable part of a bullpen next season, but do not mistake him for a young flamethrowing specialist or anything along those lines. He has shown himself capable of missing bats at a solid rate, but he will need to exhibit better control to be as effective as he can be. He would definitely be worth the same contract Park signed, but if a bidding war breaks out, he isn’t likely to be worth the money.

We hoped you liked reading Mighty Joe Nelson by Eric Seidman!

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Eric is an accountant and statistical analyst from Philadelphia. He also covers the Phillies at Phillies Nation and can be found here on Twitter.

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Eric, love the article! I think Nelson is a interesting pick-up for a team with bullpen needs.

A quick side question. To figure out runs gained for working in high leveraged situations you multiplied the LI by 1.20-1.45. What exactly is the ‘1.20-1.45’ value representing?


On second look, I think I misread you. I assume the 1.20-1.45 is the leverage score. But how do you turn a leverage score into runs is my main question.

Eric Seidman


For relievers, we find their runs above replacement and then multiply it by the leverage index. So, for someone like K-Rod, if we say he is +10 runs, with a 1.75 LI, he would be worth +17.5 runs. For Nelson, I figured that he would be between 1.20-1.45, higher than his 1.16 from 2008, given that so many teams are after him, and that teams don’t go crazy like this over someone they do not plan on using.