MLB Daily DeltaWeek 25 · September 10, 2026
Engraved portrait of Jack Perkins
week 25
this weekBUY-LOW
last weekBUY-LOW

Jack Perkins

ATH·P
data as of September 10, 2026·week 25
Buy Low luck-free xERA 4.06 sits 0.04 below league, a real arm the ERA is hiding; fastball velocity stable and above league, the arm is fine — BABIP-against 0.330 elevated and unstable, bloating the ERA; buy the player, not the number.high 0.90
ROSK 7ERA 3.93WHIP 1.35W 0–1SV 0–1

Perkins is a buy-low — the ERA is hiding a real arm.

His ERA sits at 6.53, and that number is doing him dirty. His BABIP-against is .330, 35 points above the league average of .295, and BABIP-against needs around 800 balls in play to be reliable — he has 297. That gap is luck, not a signal about his pitching. Strip out the noise and his expected ERA is 4.06, actually a hair below league average. The strikeout rate backs it up at 25.2%, above league, and his swinging-strike rate is above league too. His fastball is averaging 95.7 mph, above average, and the velocity has been stepping up. This is a pitcher whose surface line is being dragged down by bounces. Buy low.

VS His Norm

  • Walk %9.9%—+1.2% ▲vs his ~8.7% career norm
  • Strikeout %25.2%—+0.7% ▲vs his ~24.5% career norm

Drivers

  • xeraSIGNALluck-free xERA 4.06 sits 0.04 below league — a real arm the ERA is hiding
  • babip_againstNOISEBABIP-against 0.330 elevated and unstable — bloating the ERA
  • p_fastball_veloSIGNALfastball velocity stable and above league — the arm is fine
metric · nowrolling trajectoryvs. leaguestabilized?
Hard-Hit % Allowed37.3%
37.3%*
lg avg 40.0% ▼−2.7%vs his norm —
297 / 50 BBE
Barrel % Allowed8.8%
8.8%*
lg avg 8.0% ▲+0.8%vs his norm —
297 / 60 BBE
xwOBA Allowed.311
believable since Jun 22.311*
lg avg .315 ▼−.004vs his norm —
473 / 200 TBF
xERA4.06
4.06*
lg avg 4.10 ▼−0.04vs his norm —
473 / 200 TBF
ERA6.53
6.53*
lg avg 4.10 ▲+2.43vs his norm —ERA is above the ~4.10 league average — expect it to fall.
103.3 / 200 IP
Strikeout %25.2%
norm25.2%*
lg avg 22.0% ▲+3.2%vs his norm +0.7% ▲
473 / 70 TBF
Walk %9.9%
norm9.9%*
lg avg 8.0% ▲+1.9%vs his norm +1.2% ▲
473 / 170 TBF
BABIP Against.330
.330*
lg avg .295 ▲+.035vs his norm —BABIP Against is above the ~.295 league average — expect it to fall.
297 / 800 BIP
Swinging-Strike %12.8%
12.8%*
lg avg 11.0% ▲+1.8%vs his norm —
473 / 60 TBF
Chase %33.5%
33.5%*
lg avg 28.5% ▲+5.0%vs his norm —
473 / 60 TBF
Fastball Velo95.7 mph
95.7 mph*
lg avg 94.0 mph ▲+1.7 mphvs his norm —
1844 / 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% 25.2%→25.0%signal7 K — K% 25.2% (signal) tempered to career ~24.5% → projected 25.0% over ~6 remaining IP.
xERA 4.06signal3.93 ERA — xERA 4.06 (signal) blended 65% skill / 35% league 3.70 at 28 IP.
BB% 9.9% + contactsignal1.35 WHIP — a 10% walk rate plus BABIP-against 0.308 gives a 1.42 skill WHIP, blended 6…
run support + role0-1 W — wins ride run support and how deep he goes, not just skill.
role (closer)0-1 SV — role: closer.
rosterdrop4 SV, 3.93 ERA

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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