MLB Daily DeltaWeek 15 · July 3, 2026
Portrait of Martín Pérez
Martín Pérez
ATL · P
Change to
Portrait of Mitch Keller
Mitch Keller
PIT · P
Change to
Who's more valuable, rest of season

Too close to call.

They split your categories 22. Take whoever fills a bigger need.

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

Martín Pérez wins 2 (ERA, WHIP); Mitch Keller wins 2 (K, W); SV n/a.

04

Under the hood

Underlying skill — each value vs league avg
Fastball Velolg 94.0 · higher = better
Martín Pérez
90.0
Mitch Keller
93.4
Swinging-Strike %lg 11.0% · higher = better
Martín Pérez
9.5%
Mitch Keller
10.0%
Strikeout %lg 22.0% · higher = better
Martín Pérez
19.5%
Mitch Keller
18.2%
Chase %lg 28.5% · higher = better
Martín Pérez
26.2%
Mitch Keller
29.2%
Hard-Hit % Allowedlg 40.0% · lower = better
Martín Pérez
36.8%
Mitch Keller
41.5%
Barrel % Allowedlg 8.0% · lower = better
Martín Pérez
6.8%
Mitch Keller
6.2%
xwOBA Allowedlg .315 · lower = better
Martín Pérez
.323
Mitch Keller
.343
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
Martín Pérez
2.045.42
lg xERA 4.10
now 2.79
4.26
Mitch Keller
2.045.42
lg xERA 4.10
now 4.35
4.67
WHIPlower is better
Martín Pérez
.9401.49
now 1.06
1.36
Mitch Keller
.9401.49
now 1.17
1.37

Volume · rest of season
Strikeoutshigher is better
Martín Pérez
4065.80
now 42
50
Mitch Keller
4065.80
now 51
59
Winshigher is better
Martín Pérez
.00010.40
now 3
25
Mitch Keller
.00010.40
now 5
48

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

If you already own them — trade angle
Sell HighMartín Pérez — sell high. His value is peaking; good time to trade him.conf 0.95
SellMitch Keller — sell.conf 0.81
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