Over the course of his minor league career, Henry Rodriguez has put up some dazzling numbers. But, while his strikeout numbers are extremely impressive, his oft-putrid walk totals "dazzle" in another way. Rodriguez has struck out 416 batters in just 323 minor league innings, for a whopping 11.59 K/9. However, he's walked 238, for an ugly 6.63 BB/9 and below-average 1.75 K/BB.
When you watch Rodriguez pitch, it's easy to see how these results come about. His fastball regularly touches 100 mph and sits at 98, and he has a solid slider, as well. His power repertoire induces plenty of swings and misses. Still, he doesn't have pristine mechanics, and doesn't do a very good job of staying closed in his delivery, leading to a lot of bad counts and walks.
What's statistically interesting with Rodriguez is that his walk and strikeout numbers are so far out of the norm that it's difficult to get a good picture of how good he ultimately is. So, given his likely high strikeout totals, how good does his command have to be for the power righty to be an effective big league pitcher?
Rodriguez's minor league equivalent strikeout rate for his Triple-A performance (14.26 K/9 career in AAA) is about 12 K/9. That means that if he pitches the same as he did in Triple-A, he'll strike out about 12 batters per nine in the majors.
Rodriguez isn't a groundball artist (career 48.6% GB rate), but he keeps the ball in the infield enough that he shouldn't have a huge homer problem in the majors. With a roughly average grounder rate, he'll likely have a roughly average homer rate, so it likely won't push his overall performance very far in either a positive or negative direction.
Good to know. But then, how many can he afford to walk?
Well, let's be conservative and say Rodriguez will allow about .8 homers per nine in the majors, which is a little better than average (which would be expected in the pitcher-friendly park in Oakland), and strike out 12 batters per nine.
If we look at the formula for FIP (Fielding Independent Pitching), it is ((13HR+3BB-2K)/IP)+3.2.
Plugging our homer and strikeout numbers into that formula (over nine innings), we get (((13*.8)+(3BB)-(2*12))/9)+3.2
That simplifies to ((3BB-13.6)/9)+3.2.
Let's say we want to see how many Rodriguez can walk in order to get an ERA of 4.00. That means we have to solve the equation ((3x-13.6)/9)=(4-3.2).
I know, I know…I don't like algebra either.
But anyway, the answer is 6.93.
So that means that Rodriguez can afford to walk 6.93 batters per nine to post a 4.00 ERA.
That ERA, though, is the bare minimum to be a serviceable reliever, and it would be a shame for Rodriguez to be just the second coming of Santiago Casilla.
So, how about 3.50, then? That would be 5.43 BB/9.
A 3.93 BB/9, barely competent for most pitchers, would net Rodriguez a FIP just below 3.00. For each half a run of ERA, subtract 1.5 walks per nine.
Rodriguez's incredible stuff and strikeout totals net him a large margin for error, but it looks like he'll need to at least keep the walk rate down to about 5 BB/9 to post a low-3's ERA. An average walk rate would give him an ERA below 3.00, and make him a dynamic shutdown reliever.
Here's hoping Rodriguez is able to make the necessary adjustments to get to that level.