Colorado Rockies: 2017 performance based on fastball velocity

The Tiers

• Tier 1 belongs to the flamethrowers. These guys have fastballs that average 93 mph or faster. Some examples in this group who the Rockies see often include divisional opponents Clayton Kershaw, Jeff Samardzija and Taijuan Walker.
• Tier 2 is our average group, with fastballs that average 91.1 mph to 92.9 mph. Common Rockies opponents in this range include Johnny Cueto, Alex Wood, and Patrick Corbin.
• Tier 3 is home to the hurlers who tend to rely a bit more on location and changing speeds, rather than overpowering the man in the batter’s box. Their fastballs average velocities of 91 mph and below. That’s not to say these guys are easy to hit, as this group includes the likes of Zack Greinke, Hyun-jin Ryu, and Jered Weaver.

With that established, I went through the Rockies entire 2017 schedule and documented the pitcher they faced in each game, which velocity tier that pitcher fell in, and the box score line the Rockies racked up against him. With starting pitchers leaving the game at different points in the game each day, I went ahead and averaged the totals per nine innings to standardize the data. Now for the results!

The Results

Tier 1 (93.0+ MPH)

• 73 Games Played (.575 Win%)
• 5.35 Average IP
• 9.87 Hits/9
• 3.18 Walks/9
• 8.74 Strikeouts/9
• 1.36 Home Runs/9
• 5.42 ERA

Tier 2 (91.1-92.9 MPH)

• 57 Games Played (.421 Win%)
• 5.36 Average IP
• 9.95 Hits/9
• 3.47 Walks/9
• 8.45 Strikeouts/9
• 1.12 Home Runs/9
• 4.98 ERA

Tier 3 (91.0 MPH and Below)

• 32 Games Played (.656 Win%)
• 5.42 Average IP
• 10.38 Hits/9
• 3.01 Walks/9
• 7.17 Strikeouts/9
• 1.77 Home Runs/9
• 5.56 ERA

*Boldface type indicates which tier the Rockies performed best against in each respective box score line item

There’s a lot to unpack here. The first point I’ll direct your attention to is just how many games the Rockies played against Tier 1, hard-throwing pitchers in 2017. Recall that I split the total number of starting pitchers into equal thirds, so probability-wise there’s reason to anticipate playing roughly equal numbers of games against each tier. Reality, however, had the Rockies facing high velocity pitchers more than twice as much as they faced the third tier precision guys.

As I set out to do this research, I had some guesses as to how the data would play out. Some of these guesses panned out, while others were off, sometimes way off. For example, I anticipated that strikeouts would be proportional with fastball velocity, and that turned out to be true. The faster the pitchers threw, the more times the Rockies made that U-turn from the batter’s box back to the dugout. Similarly, I correctly predicted that hits would be inversely  proportional to velocity (hits go up as velocity goes down).