Nick Castellanos · RHH · 1B / RF / DH · turns 35 in March 2027
There's a bunch of great foundation to build on here. But compared to your 2017, 2018 and 2021 seasons, there are some major differences beyond the slight, expected decline in bat speed and reaction time. Your leg kick has gotten shorter and peaks late, and for some reason your stride has gotten shorter.
I've built tools that analyze hitters from their own data and swing metrics. You can help me bridge the gap between my passion for and understanding of swing mechanics and knowing how to fix specific flaws, using your MLB experience fixing them yourself or watching other hitters do it.
Where you are now, where we're taking it by spring, and your best season for reference.
100 is league average. Tap a bar for the season.
Proposed dates. Hover or tap a day for the details.
Your OK to ask for your own tracking data through your agent: the Hawk-Eye skeleton and bat data from the Reds (2020-21), Phillies (2022-25) and Padres (2026). The 2021 skeleton lets us compare your best swing with now in 3D. The labor agreement runs out December 1, so the requests should go out now.
Your swing
A breakdown of two 96 mph fastballs you hit for doubles, filmed from the same center-field camera. Both swings are synced to the pitcher's release point. Drag the slider or step through the frames; every frame has its own timestamp.
Median leg-lift start across 305 swings: 541 ms before release in 2021, 404 ms in 2026. On the two swings above, the gap is 67 ms.
On these two swings, your knee reached the top of the kick 117 ms later in 2026. In 2021 it was already coming down at release.
Median foot down: 212 ms after release in 2021, 210 ms in 2026. The kick has less time to get there, so it comes down faster.
One Hard-Hit Fastball per Year
Photos at contact
Timing
In every season your front foot lands about 0.21 s after the pitcher lets go, roughly 0.2 s before the ball reaches you. What changed is the gather before that. In 2021 your kick started earliest and reached the top before release.
305 home-feed center-field swings from Baseball Savant video, 2017-26 (2020 not pulled). Lift, knee top and foot down come from the pose skeleton's front-ankle track; hands and contact from frame review. 60 fps (±8 ms), 2017 at 30 fps (±17 ms). The thin line under each circle covers the middle half of that season's lift starts.
Month by month, 2023-26
Video and Hawk-Eye measure different things and still rise and fall together. May 2026 is the low point on both: 527 ms and 7.5 in.
Gather = leg lift to foot down, median of 136 home-feed swings. Stride = Hawk-Eye forward stride from Savant foot tracking. March folded into April, October into September.
Statcast swing timing
A slower bat has to start sooner to catch 95. In 2026 you were rarely late on fastballs and got on top of them more than almost any hitter. Being early on breaking balls goes back years.
Baseball Savant swing timing. The pill is your percentile against hitters with 100+ swings on that pitch type. 2023 is the second half only.
Bat and path · Hawk-Eye, 2023-26
From 2023 to 2026 you lost 2.7 mph of bat speed, the largest drop among 55 tracked hitters aged 30 to 35. You won 2.3 mph back once already, from April to September 2024, and that stretch is the template for this winter.
Baseball Savant bat-tracking leaderboard, monthly, competitive swings. March folded into April. The dashed line is the MLB average for that season.
Swing shape vs MLB
Percentile against qualified hitters on Baseball Savant. Orange means it costs you, blue means it helps.
Breaking balls, seen from above
Each bat is drawn where it meets the ball's path, looking down from above with the pitcher at the top. On breaking balls you hit or foul off, the barrel meets the ball closer to your body and aims toward center. On the ones you miss, it's out in front and pulled across.
Hawk-Eye bat tracking on breaking balls (sliders, sweepers, curves, knuckle curves, slurves). Out front = inches in front of your body where the bat crosses the ball's path. Drawing to scale for those two numbers.
Your feet, seen from above
Hawk-Eye tracks your toes and heels on every pitch. Back foot on the left, pitcher to the right. The dashed shoe is where the typical right-handed hitter's front foot is at contact. Every year it's been tracked, your base at contact has been narrower than 93-98% of right-handed hitters.
Baseball Savant batting-stance foot tracking, from the second half of 2023. Widths are between the centers of your feet. Stride is Savant's forward stride.
What broke · regression checklist
These are the usual ways a hitter in his 30s slips. Normal aging costs 0.1-0.3 mph of bat speed a year and pushes contact deeper. You lost more than that and your contact got earlier, which points to compensation. A sign only moves to Confirmed when video or a sensor shows it.
The rebuild · November 2026 to March 2027
Your foot already lands on time, so we don't re-time the stride. We restore the early, long 2021 gather, the 15-inch stride and the wait after landing, then add speed on top. Each fix has one cue for you and one number for me to check.
Proposed dates · hover or tap a day
The approach work (Part 2) runs alongside. A club showcase follows in March.
Weekly cage targets
If lift timing misses two weeks in a row, we stop adding volume and go back to tee and front toss on the gather.
Daily cage · about 25 minutes, under 60 swings
Bat speed after 33
87 hitters aged 33 or older. Only 3 gained 1.8 mph or more in a season.
13 who lost 1 mph or more. 4 won 1 mph back the next year.
What the research says moves bat speed:
| Overload and underload bats, 8 weeks | +6.2% |
| Light-bat warm-up, same day | +1.3-4.9% |
| Rotational med-ball, 12 weeks (hitter's throw) | +10.6% |
| Lead-leg force vs bat speed | r = 0.62-0.66 |
| Heavy donut on deck | slower |
Liu 2011; Finlay 2022; Szymanski 2007; Orishimo 2024; Montoya 2009. Driveline hitters average +2 mph per off-season, but Driveline's own model projects under 1 mph for a hitter your age.
2017-2026
Pick a group of numbers, then tap a season to see what went up, what went down, and what your stance looked like month by month. Green marks your better end of the range, red your worse.
Tracking data · skeletons
Everything here comes from public data and center-field video. Three of the twelve warning signs need 3D to check: hip-shoulder separation, the front-leg block, and whether your front side opens after landing.
2021, top of the kick. Skeleton from a pose model on the broadcast frame: 17 points, 60 frames a second, one camera.
305 center-field swings from 2017-26, plus 426 side and replay views. The only way to measure 2017, 2018 and 2021.
Synced cameras at 240+ fps, two force plates, a bat sensor and ball tracking. This is where the rebuild gets measured.
Hawk-Eye tracks every player's skeleton on every pitch: 18 points in 2020, 29 by 2024. Clubs keep the full skeleton.
Before we ask
The kit
| Tool | Job | Cost |
|---|---|---|
| Force platesCore | Front-leg block and left-right balance, in November, January and February | Facility time |
| Markerless labCore | Full kinematic sequence, in November, January and February | $7,500 (Driveline, 2 days) |
| Two phones at 240 fps | Center-field line and open side, every two weeks | Free |
| Blast sensor | Daily bat-speed trend against your own baseline | $150 + $75/yr |
| Trackman or Full Swing KIT | Bat speed numbers a front office believes | Session, or $6,499 |
Bat sensors read 5-17% low against lab capture (Blast about 16%), so they're for trends only. Bat speed for clubs gets proven on Hawk-Eye or a calibrated Trackman.
Sources and method
Public data pulled October 2, 2026, covering the regular season through your last game on May 31, 2026. 2026 is 122 plate appearances, so read it as a direction, not a verdict.