MLB Daily DeltaWeek 27 · September 27, 2026
Portrait of Dennis Santana
Dennis Santana
AZ · P
Change to
Portrait of Riley O'Brien
Riley O'Brien
STL · P
Change to
Who's more valuable, rest of season

Too close to call.

They split your categories 1–1, 2 even. Take whoever fills a bigger need.

Head-to-head
K
◀
ERA
WHIP
▶
W
SV n/a

Dennis Santana wins 1 (ERA); Riley O'Brien wins 1 (WHIP); 2 even; SV n/a.

04

Under the hood

Underlying skill — each value vs league avg
Fastball Velolg 94.0 · higher = better
Dennis Santana
94.1
Riley O'Brien
97.7
Swinging-Strike %lg 11.0% · higher = better
Dennis Santana
12.9%
Riley O'Brien
11.9%
Strikeout %lg 22.0% · higher = better
Dennis Santana
20.4%
Riley O'Brien
23.2%
Chase %lg 28.5% · higher = better
Dennis Santana
33.4%
Riley O'Brien
29.2%
Hard-Hit % Allowedlg 40.0% · lower = better
Dennis Santana
40.9%
Riley O'Brien
42.2%
Barrel % Allowedlg 8.0% · lower = better
Dennis Santana
8.5%
Riley O'Brien
7.5%
xwOBA Allowedlg .315 · lower = better
Dennis Santana
.333
Riley O'Brien
.340
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
Dennis Santana
2.565.45
lg xERA 4.10
now 4.81
4.39
Riley O'Brien
2.565.45
lg xERA 4.10
now 3.20
4.53
WHIPlower is better
Dennis Santana
.9001.68
now 1.48
1.37
Riley O'Brien
.9001.68
now 0.99
1.36

Volume · rest of season
Strikeoutshigher is better
Dennis Santana
4037.80
now 19
0
Riley O'Brien
4037.80
now 27
0
Winshigher is better
Dennis Santana
.0004.20
now 2
0–0
Riley O'Brien
.0004.20
now 3
0–0

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

If you already own them — trade angle
SellDennis Santana — sell.conf 0.75
SellRiley O'Brien — sell.conf 0.81
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