MLB Daily DeltaWeek 27 · September 30, 2026
Cesar Perdomo
SF · P
Change to
Portrait of Devin Williams
Devin Williams
NYM · P
Change to
Who's more valuable, rest of season

Too close to call.

They split your categories 0–0, 4 even. Take whoever fills a bigger need.

Head-to-head
K
ERA
WHIP
W
SV n/a

Cesar Perdomo wins 0 (none); Devin Williams wins 0 (none); 4 even; SV n/a.

04

Under the hood

Underlying skill — each value vs league avg
Fastball Velolg 94.0 · higher = better
Cesar Perdomo
93.0
Devin Williams
93.9
Swinging-Strike %lg 11.0% · higher = better
Cesar Perdomo
9.9%
Devin Williams
17.5%
Strikeout %lg 22.0% · higher = better
Cesar Perdomo
13.5%
Devin Williams
28.3%
Chase %lg 28.5% · higher = better
Cesar Perdomo
27.9%
Devin Williams
38.6%
Hard-Hit % Allowedlg 40.0% · lower = better
Cesar Perdomo
42.2%
Devin Williams
29.7%
Barrel % Allowedlg 8.0% · lower = better
Cesar Perdomo
7.2%
Devin Williams
4.5%
xwOBA Allowedlg .315 · lower = better
Cesar Perdomo
.324
Devin Williams
.278
stabilized — trust it · small sample yet · dashed = league avg · right = better
05

The tape

Rest-of-season projection · bold = leads
rest-of-season projection current season projection range
Rate · earned-run quality
ERAlower is better
Cesar Perdomo
26.66
lg xERA 4.10
now 2.25
3.70
Devin Williams
26.66
lg xERA 4.10
now 5.40
3.70
WHIPlower is better
Cesar Perdomo
.9001.77
now 1.00
1.24
Devin Williams
.9001.77
now 1.55
1.24

Volume · rest of season
Strikeoutshigher is better
Cesar Perdomo
4043.40
now 4
0
Devin Williams
4043.40
now 31
0
Winshigher is better
Cesar Perdomo
.0004.20
now 0
0–0
Devin Williams
.0004.20
now 3
0–0

SV — not applicable. Both pitch out of the rotation.

If you already own them — trade angle
Hold · wait & seeCesar Perdomo — hold.conf 0.50
Buy LowDevin Williams — buy low. The dip is a window to acquire.conf 0.90
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