MLB Daily DeltaWeek 25 · September 10, 2026
Engraved portrait of Ryan Zeferjahn
week 25
this weekBUY
last weekHOLD

Ryan Zeferjahn

CHC·P
data as of September 10, 2026·week 25
flipped from HOLD on September 10, 2026
Buy stable xERA 3.20, 0.90 below league, production is earned; velocity stable and above league; add now.high 0.87
ROSK 6ERA 3.20WHIP 1.33W 0–1SV 0–0

Zeferjahn is a buy — the stuff is real and the sample proves it.

His expected ERA is 3.20, a full run below the league average of 4.10, and he has faced enough batters for that number to be reliable. The skill holds up underneath it. He strikes out 31.2% of hitters, well above the league rate of 22%, and his fastball sits at 97.4 mph, three miles per hour harder than average — and that velocity has been climbing across the sample while his expected ERA has been stepping down. He does walk 13.1% of batters, and that rate will cost him some runs, but his expected wOBA allowed is .278 against a league average of .315, so the contact he gives up is weak. Nothing here is propped up by luck. Buy. Deep-league only: 6 K, 3.20 ERA, 1.33 WHIP makes him a stashable asset, not a must-add.

VS His Norm

  • Strikeout %31.2%—+3.5% ▲vs his ~27.7% career norm
  • Walk %13.1%—−0.4% ▼vs his ~13.5% career norm

Drivers

  • xeraSIGNALstable xERA 3.20, 0.90 below league — production is earned
  • p_fastball_veloSIGNALvelocity stable and above league
metric · nowrolling trajectoryvs. leaguestabilized?
Hard-Hit % Allowed36.1%
36.1%*
lg avg 40.0% ▼−3.9%vs his norm —
147 / 50 BBE
Barrel % Allowed6.1%
believable since May 286.1%*
lg avg 8.0% ▼−1.9%vs his norm —
147 / 60 BBE
xwOBA Allowed.278
.278*
lg avg .315 ▼−.037vs his norm —
282 / 200 TBF
xERA3.20
3.20*
lg avg 4.10 ▼−0.90vs his norm —
282 / 200 TBF
ERA4.17
4.17*
lg avg 4.10 ▲+0.07vs his norm —ERA is above the ~4.10 league average — expect it to fall.
64.7 / 200 IP
Strikeout %31.2%
norm31.2%*
lg avg 22.0% ▲+9.2%vs his norm +3.5% ▲
282 / 70 TBF
Walk %13.1%
norm13.1%*
lg avg 8.0% ▲+5.1%vs his norm −0.4% ▼
282 / 170 TBF
BABIP Against.266
.266*
lg avg .295 ▼−.029vs his norm —BABIP Against is below the ~.295 league average — expect it to rise.
147 / 800 BIP
Swinging-Strike %13.0%
13.0%*
lg avg 11.0% ▲+2.0%vs his norm —
282 / 60 TBF
Chase %25.3%
25.3%*
lg avg 28.5% ▼−3.2%vs his norm —
282 / 60 TBF
Fastball Velo97.4 mph
97.4 mph*
lg avg 94.0 mph ▲+3.4 mphvs his norm —
1183 / 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% 31.2%→29.7%signal6 K — K% 31.2% (signal) tempered to career ~27.7% → projected 29.7% over ~5 remaining IP.
xERA 3.20signal3.20 ERA — regresses up toward xERA 3.20 (signal): elite skill, but overperforming even…
BB% 13.1% + contactsignal1.33 WHIP — a 13% walk rate plus BABIP-against 0.290 gives a 1.38 skill WHIP, blended 6…
run support + role0-1 W — wins ride run support and how deep he goes, not just skill.
role (setup)0-0 SV — role: setup, in the save mix only situationally.
rosterdeep3.20 ERA, 1.33 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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