MLB Daily DeltaWeek 31 · October 26, 2026
Engraved portrait of Jack Perkins
week 31
this weekBUY-LOW
last weekBUY-LOW

Jack Perkins

ATH·P
data as of October 26, 2026·week 31
Buy Low luck-free xERA 4.09 sits 0.01 below league, a real arm the ERA is hiding; fastball velocity stable and above league, the arm is fine — BABIP-against 0.323 elevated and unstable, bloating the ERA; buy the player, not the number.high 0.90
ROSK 0ERA 3.95WHIP 1.33W 0–0SV 0–0

Perkins is a buy-low — the ERA is BABIP noise over a real arm.

His fastball is sitting at 95.7 mph and climbing, 1.7 mph above league average, and it's been stable across the sample. That is the arm. The ERA of 6.10 is not. His BABIP-against is .323, 28 points above league average, and it needs around 800 balls in play to become reliable — he has 340. That gap is luck, not skill. Strip it out and his expected ERA is 4.09, right at league average, and his expected wOBA allowed of .311 is slightly better than league. He also misses bats: a 25.9% strikeout rate and 13.1% swinging-strike rate, both above average. The skills are stable and the surface is not. Buy low.

VS His Norm

  • Strikeout %25.9%—+1.4% ▲vs his ~24.5% career norm
  • Walk %9.4%—+0.7% ▲vs his ~8.7% career norm

Drivers

  • xeraSIGNALluck-free xERA 4.09 sits 0.01 below league — a real arm the ERA is hiding
  • babip_againstNOISEBABIP-against 0.323 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 —
340 / 50 BBE
Barrel % Allowed8.8%
8.8%*
lg avg 8.0% ▲+0.8%vs his norm —
340 / 60 BBE
xwOBA Allowed.311
believable since Jun 22.311*
lg avg .315 ▼−.004vs his norm —
541 / 200 TBF
xERA4.09
4.09*
lg avg 4.10 ▼−0.01vs his norm —
541 / 200 TBF
ERA6.10
6.10*
lg avg 4.10 ▲+2.00vs his norm —ERA is above the ~4.10 league average — expect it to fall.
121 / 200 IP
Strikeout %25.9%
norm25.9%*
lg avg 22.0% ▲+3.9%vs his norm +1.4% ▲
541 / 70 TBF
Walk %9.4%
norm9.4%*
lg avg 8.0% ▲+1.4%vs his norm +0.7% ▲
541 / 170 TBF
BABIP Against.323
.323*
lg avg .295 ▲+.028vs his norm —BABIP Against is above the ~.295 league average — expect it to fall.
340 / 800 BIP
Swinging-Strike %13.1%
13.1%*
lg avg 11.0% ▲+2.1%vs his norm —
541 / 60 TBF
Chase %34.3%
34.3%*
lg avg 28.5% ▲+5.8%vs his norm —
541 / 60 TBF
Fastball Velo95.7 mph
95.7 mph*
lg avg 94.0 mph ▲+1.7 mphvs his norm —
2101 / 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% 25.9%→25.5%signal0 K — K% 25.9% (signal) tempered to career ~24.5% → projected 25.5% over ~0 remaining IP.
xERA 4.09signal3.95 ERA — xERA 4.09 (signal) blended 65% skill / 35% league 3.70 at 28 IP.
BB% 9.4% + contactsignal1.33 WHIP — a 9% walk rate plus BABIP-against 0.307 gives a 1.38 skill WHIP, blended 65…
run support + role0-0 W — wins ride run support and how deep he goes, not just skill.
role (closer)0-0 SV — role: closer.
rosterdrop3 SV, 3.95 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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