What changed for Ha-Seong Kim.
From 2025 to 2026, Ha-Seong Kim's BB% moved from 8.3% to 11.0%. Here's everything else the data sees that changed.
The swing, launch, and flight
Every path below is a real Statcast batted ball, reconstructed from its exit velocity, launch angle, spray direction, distance, and outcome. Current shape: 80.4 mph average exit velocity, 19.8° average launch angle, 17.7% hard-hit.
This view describes the current-season batted-ball shape. The year-over-year tables below provide the comparison behind the story.
Something has changed for Ha-Seong Kim, now 31, between 2025 and 2026. We went through what the data can actually measure, including contact, plate approach, swing shape, and the results they produce, to separate the signal from the noise. The clearest gain: BB% moved from 8.3% to 11.0%, which now sits in the 73th percentile leaguewide. It hasn't been all one direction. OPS has slipped from 0.641 to 0.239, but the trade has largely worked so far.
The Results
On the bottom-line production (what it all adds up to), this is the soft spot. Kim has gone the wrong way on OPS (0.641→0.239), xSLG (0.461→0.294), and wOBA (0.291→0.135), which is worth watching even if the headline numbers hold up.
| Metric | 2025 | 2026 | Change | League now |
|---|---|---|---|---|
| xwOBA | 0.297 | 0.212 | ▼ -0.085 | 0th |
| wOBA | 0.291 | 0.135 | ▼ -0.156 | 0th |
| xSLG | 0.461 | 0.294 | ▼ -0.167 | 0th |
| OPS | 0.641 | 0.239 | ▼ -0.402 | 0th |
The biggest move is OPS, down from 0.641 to 0.239 (-0.402). This is where things have gone the wrong way.
Contact Quality
On the quality of contact (how hard and how flush he's hitting the ball), this is the soft spot. Kim has gone the wrong way on Exit Velo (89.2 mph→85.1 mph), Hard-Hit% (43.3%→22.4%), and Sweet-Spot% (35.1%→20.4%), which is worth watching even if the headline numbers hold up.
| Metric | 2025 | 2026 | Change | League now |
|---|---|---|---|---|
| Exit Velo | 89.2 mph | 85.1 mph | ▼ -4.0 | 11th |
| Barrel% | 3.6% | 2.4% | ▼ -1.2 pts | 12th |
| Hard-Hit% | 43.3% | 22.4% | ▼ -20.8 pts | 2th |
| Sweet-Spot% | 35.1% | 20.4% | ▼ -14.7 pts | 0th |
The biggest move is Exit Velo, down from 89.2 mph to 85.1 mph (-4.0). This is where things have gone the wrong way.
Plate Approach
On his approach at the plate (what he swings at and how often he misses), it's a genuine mix. Kim has gained ground on BB% (8.3%→11.0%), while slipping on K% (20.3%→26.8%), Chase% (21.2%→24.4%), and Whiff% (14.6%→17.7%). The net picture is a real shift in profile, not a simple up-or-down.
| Metric | 2025 | 2026 | Change | League now |
|---|---|---|---|---|
| Chase% | 21.2% | 24.4% | ▼ +3.3 pts | 81th |
| Whiff% | 14.6% | 17.7% | ▼ +3.1 pts | 75th |
| K% | 20.3% | 26.8% | ▼ +6.5 pts | 18th |
| BB% | 8.3% | 11.0% | ▲ +2.6 pts | 73th |
The biggest move is K%, up from 20.3% to 26.8% (+6.5 pts).
Swing & Batted-Ball Shape
On his swing and batted-ball shape (the mechanical fingerprint behind the changes above), it's a genuine mix. Kim has gained ground on Launch Angle (15.6°→17.2°), Bat Speed (68.5 mph→70.1 mph), and Pull% (43.3%→46.9%), while slipping on Ground-Ball% (37.3%→44.9%) and Swing Length (6.9 ft→7.0 ft). The net picture is a real shift in profile, not a simple up-or-down.
| Metric | 2025 | 2026 | Change | League now |
|---|---|---|---|---|
| Launch Angle | 15.6° | 17.2° | ▲ +1.7 | 78th |
| Pull% | 43.3% | 46.9% | ▲ +3.7 pts | 60th |
| Oppo% | 25.4% | 28.6% | ▲ +3.2 pts | 68th |
| Ground-Ball% | 37.3% | 44.9% | ▼ +7.6 pts | 31th |
| Bat Speed (2024+) | 68.5 mph | 70.1 mph | ▲ +1.6 | 53th |
| Swing Length (2024+) | 6.9 ft | 7.0 ft | ▼ +0.1 | 71th |
The biggest move is Launch Angle, up from 15.6° to 17.2° (+1.7).
The takeaway
Bottom line: between 2025 and 2026, the broad picture is a step back, and it's showing in the results. More of Kim's markers are sliding than improving. It's worth re-checking as the sample grows, but the direction is already readable in the numbers.
How to read this
- Sample sizes are modest (2025 192 PA, 2026 82 PA), so read the magnitude of these changes with some caution.
- This compares what the data can measure (contact, approach, swing and batted-ball shape). Stance, hand position, and leg-kick changes are not in the public data and are not claimed here.