Power vs. finesse. It's the classic debate. Spanning over 60 feet 6 inches, the difference between a 90 mile-per-hour fastball and a 95-MPH heater makes up a couple hundredths of a second. More importantly, those 5 MPH represent the difference between fringe stuff and an above-average Major League fastball. So how do pitchers compensate for shortcomings in velocity?
Throwing left handed is the simplest solution. The demand for southpaws is so great and the supply so scarce that the price for a lefty far surpasses that of an equally talented righty. Put another way, left-handed pitchers can accomplish more with less. So left-handed pitchers were excluded from my sample.
My sample consisted of of over 100,000 pitches from the past two calendar years. I grouped pitches by batter handedness as well as by velocity--depending on whether the velocity rounded off to 90 MPH or 95.
First, I looked at pitch location. The color scales that portray run value are the same for both images, so you can compare them directly.
Soft tossers can't survive by living up in the zone. A 90-MPH pitch can be thrown in the perfect spot in on the hands, and it still won't have the same success on average as a 95-MPH pitch that misses by half a foot. However, pitchers who throw 90 experience just as much success throwing down and away to same-handed batters as pitchers who throw 95. In this regard, pitch location can be a true equalizer. Joakim Soria locates his 90-MPH fastball so well that it's in the upper echelon of all fastballs, while Daniel Cabrera has located his 95 MPH fastballs so poorly that he's out of the league.
I also looked at pitch movement. The magnitude of the effect of pitch movement is much smaller than that of pitch location. Below, run value is plotted against horizontal movement in the solid-line portion of the graph, while a histogram for horizontal movement can be found at the bottom.
A 90-MPH pitch with average movement is a disaster. Even a 90-MPH pitch with great tail can't match an average 95-MPH pitch unless the 90-MPH pitch also has sink on it. But if a pitcher can really cut the ball so that it acts as a cutter, or even a slider for some, it can match an average 95-MPH fastball.
And vertical movement:
I find this to be an interesting trend. The 90-MPH pitchers are better off throwing rising fastballs, while 95-MPH pitchers are just as well off throwing sinkers or risers, so long as they stay out of that ten-inch danger zone to which the batter is accustomed.
In combining both horizontal and vertical movement, it's evident that Peter Moylan generates enough movement on his fastball to throw it at elite levels, while Cabrera, again, has a mediocre-to-awful fastball in spite of his velo. Remember, I'm only including 95 MPH pitches, so imagine how bad his fastball must have been in 2009 at 91 MPH. Cabrera is the poster boy for pitchers who can throw gas but have no command or movement, rendering their fastball ineffective. Kevin Jepsen, Jonathan Broxton, and Brian Wilson are examples of pitchers whose 90-MPH pitches are better than most pitchers' 95s, since those guys are throwing off speed at 90. Also of note: Jenrry Mejia's fastball has excellent movement.
Mixing location and movement into a regression, here are the best 90-MPH fastballs with at least 100 thrown:
David Robertson continues to be the man. No pitcher's 90-MPH fastball penetrates the top tenth of my sample, but all of these pitchers are squarely above average. They show that 90 MPH can beat 95, especially when the 95 is coming from the likes of:
Cabrera's 95 MPH fastball was the third worst fastball in my sample, and no other 95-MPH fastball fell in the bottom 40. The 90-MPH version of Cabrera's fastball was arguably better than his previous iteration.