MLB Daily DeltaWeek 25 · September 10, 2026
Engraved portrait of Justin Slaten
week 25
this weekBUY-LOW
last weekNO CALL

Justin Slaten

BOS·P
data as of September 10, 2026·week 25
ON THE 15-DAY IL
new call
Buy Low fastball velocity stable and above league, the arm is fine — luck-free xERA 2.92 sits 1.18 below league, a real arm the ERA is hiding; BABIP-against 0.369 elevated and unstable, bloating the ERA; buy the player, not the number.high 0.90
ROSK 5ERA 3.70WHIP 1.24W 0–0SV 0

Slaten is a buy-low — his ERA is BABIP, not his arm.

His ERA is 4.60, and that number is doing him dirty. His BABIP-against is .369 against a league average of .295 — 74 points of pure noise. BABIP-against needs around 800 balls in play to stabilize and he has 90, so the gap is luck, not a signal about his pitching. Strip out the noise and his expected ERA is 2.92, more than a run better than league average, supported by a 28.5% strikeout rate and 12.8% swinging strikes, both above league. He is allowing just 4.4% barrels and 36.7% hard contact, both well clear of league. His fastball is up to 96.6 mph and still climbing, and the arm is fine. Buy low. A 3.70 ERA and 1.24 WHIP with 5 K is a deep-league hold — buy the dip before the surface corrects.

VS His Norm

  • Strikeout %28.5%—+4.7% ▲vs his ~23.8% career norm

Drivers

  • xeraNOISEluck-free xERA 2.92 sits 1.18 below league — a real arm the ERA is hiding
  • babip_againstNOISEBABIP-against 0.369 elevated and unstable — bloating the ERA
  • p_fastball_veloSIGNALfastball velocity stable and above league — the arm is fine
metric · nowrolling trajectoryvs. leaguestabilized?
Hard-Hit % Allowed36.7%
36.7%*
lg avg 40.0% ▼−3.3%vs his norm —
90 / 50 BBE
Barrel % Allowed4.4%
4.4%*
lg avg 8.0% ▼−3.6%vs his norm —
90 / 60 BBE
xwOBA Allowed.266
.266*
lg avg .315 ▼−.049vs his norm —xwOBA Allowed is below the ~.315 league average — expect it to rise.
137 / 200 TBF
xERA2.92
2.92*
lg avg 4.10 ▼−1.18vs his norm —xERA is below the ~4.10 league average — expect it to rise.
137 / 200 TBF
ERA4.60
4.60*
lg avg 4.10 ▲+0.50vs his norm —ERA is above the ~4.10 league average — expect it to fall.
31.3 / 200 IP
Strikeout %28.5%
norm28.5%*
lg avg 22.0% ▲+6.5%vs his norm +4.7% ▲
137 / 70 TBF
Walk %5.8%
norm5.8%*
lg avg 8.0% ▼−2.2%vs his norm +0.1% ▲Walk % is above his ~5.7% norm — expect it to fall.
137 / 170 TBF
BABIP Against.369
.369*
lg avg .295 ▲+.074vs his norm —BABIP Against is above the ~.295 league average — expect it to fall.
90 / 800 BIP
Swinging-Strike %12.8%
12.8%*
lg avg 11.0% ▲+1.8%vs his norm —
137 / 60 TBF
Chase %33.3%
33.3%*
lg avg 28.5% ▲+4.8%vs his norm —
137 / 60 TBF
Fastball Velo96.6 mph
96.6 mph*
lg avg 94.0 mph ▲+2.6 mphvs his norm —
508 / 50 PITCHES

5×5 ROS Outlook

rest of season

Where each category goes the rest of the way, and the skill that drives it. Tap a row to expand the full derivation.

statytdrosdriverconf
K% 28.5%→25.7%signal5 K — K% 28.5% (signal) tempered to career ~23.8% → projected 25.7% over ~4 remaining IP.
xERA 2.92noise3.70 ERA — xERA 2.92 (noise) blended 0% skill / 100% league 3.70 at 10 IP.
BB% 5.8% + contactnoise1.24 WHIP — a 6% walk rate plus BABIP-against 0.303 gives a 1.17 skill WHIP, blended 0%…
run support + role0-0 W — wins ride run support and how deep he goes, not just skill.
role (setup)0 SV — role: setup, not in the save mix.
rosterdeep3.70 ERA, 1.24 WHIP

Every projection traces to a sabermetric input. The driver and confidence shown per row are always visible; tap any row to expand the full derivation.

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