Purple Row After Dark: One Stone Too Many?

TL;DR

The Colorado Rockies' new pitching strategy shows promising early results, particularly with Tanner Gordon's evolving pitch mix. However, concerns arise over the effectiveness of his sinker, which has struggled against hitters.

Key points

Tanner Gordon's arm angle increased from 43° to 46° this season.
Gordon's sinker has been ineffective, with a .667 batting average against it.
The Rockies are focusing on refining their pitching strategy.
Gordon has primarily worked out of the bullpen so far.

Tanner GordonColorado Rockies

SCOTTSDALE, AZ - FEBRUARY 18: Pitcher, Tanner Gordon stands for a photo during media day at spring training for the Colorado Rockies at Salt River Field at Talking Stick in Scottsdale, Arizona on February 18, 2026. (Photo by RJ Sangosti/MediaNews Group/The Denver Post via Getty Images) | Denver Post via Getty Images The Rockies’ new pitching philosophy is no longer a secret. They promised to leave no stone unturned, and one month in, the results have been genuinely impressive. Depending on your preferred WAR metric, Colorado has had one of baseball’s most valuable pitching staffs — at altitude, no less. That story has been covered well, including here at Purple Row. So here’s the next question: **When does experimentation become refinement?** I started thinking about that while watching Tanner Gordon on Tuesday. The shapes of his fastball, changeup and sinker all looked…. similar. So, naturally, I spent my Tuesday night in a Baseball Savant rabbit hole. While looking at Gordon’s movement profile, the arm angle caught my eye: He is up from **43° last year to 46° this year**.

**The slot and the sinker** That arm-angle change makes the curveball experiment logical. A higher slot can help create a more vertical breaking ball, giving Gordon a different plane from the fastball/changeup/slider foundation. The sinker, though, is harder to defend. Gordon has not been given a start yet, so this is an imperfect evaluation. He has mostly worked out of the bullpen, and the sample sizes are tiny. His sinker has made up only **12%** of his pitches — **23 total**. Still, in that tiny sample, hitters are batting **.667** against it with a **2.000 slugging percentage**, **100.4 mph average exit velocity**, and no putaways. Hitters are not just seeing the sinker; they are ordering it off the menu. The concern is not only the results. It is the shape. The sinker visually lives too close to the fastball/changeup lane. If it is not creating grounders, weak contact, or a different plane, it risks becoming another version of a pitch family Gordon already has. **Fewer pitches, better fit?** The Rockies have had early success letting pitchers find footing in the bullpen, and Gordon can still offer rotation value because his command is legitimately excellent. He does not need overwhelming stuff to survive, but the pitch mix has to be coherent. Of course, pitches take time. is a useful reminder. His curveball was barely part of his mix in 2023 at **1%**, then grew to **8%** in 2024, **11%** in 2025, and **15%** this season. That is what refinement can look like: not instant reinvention, but gradual trust. Still, patience and commitment are not the same thing. The Rockies may not need Gordon to throw more pitches. They may need him to throw fewer pitches that make more sense. So, After Dark: keep developing the sinker, reduce it, or lean harder into the curveball/changeup path?

Q&A

What changes has Tanner Gordon made to his pitching this season?

Tanner Gordon has increased his arm angle from 43° to 46°, which impacts the effectiveness of his curveball and sinker.

How effective has Tanner Gordon's sinker been in games?

Gordon's sinker has been hit hard, with opponents batting .667 against it and a 2.000 slugging percentage in a small sample size.

What is the Colorado Rockies' new pitching philosophy?

The Rockies aim to leave no stone unturned in their pitching approach, focusing on experimentation and refinement to improve their staff's performance.

How does Tanner Gordon's pitch mix compare to other pitchers?

Gordon's pitch mix includes a fastball, changeup, and slider, but concerns exist that his sinker may not provide enough differentiation from these pitches.