Head to head · 2026 pitching

Luis Castillo vs Merrill Kelly

In 2026 Luis Castillo has been worth 0.2 more wins. Both lines are computed from play-by-play on the same constants, so they are measured the same way rather than quoted from two sources.

Their 2025 seasons were among each other's nearest on rate statistics.

Luis Castillo SEA

Merrill Kelly AZ

2026 season

2026 pitching. The stronger figure in each row is highlighted — for ERA, FIP, WHIP and walks that is the lower one.
Statistic	Luis Castillo	Merrill Kelly
G	29	29
GS	23	29
IP	130.2	162.0
W	4	10
SO	112	113
ERA	5.85	4.94
FIP	5.05	5.33
WHIP	1.49	1.46
K/9	7.7	6.3
BB/9	3.0	3.9
FIP−	121	127
WAR	0.0	-0.2

Postseason

Box-score figures only: October is kept out of the season constants, so there is no wOBA, FIP or dbWAR for it.

Every published postseason, pitching, summed with the rates recomputed from the counts.
Statistic	Luis Castillo	Merrill Kelly
G	6	4
GS	5	4
IP	28.0	24.0
W	2	3
SV	0	0
SO	24	28
BB	6	8
ERA	2.25	2.25
WHIP	1.04	0.83
K/9	7.7	10.5
BB/9	1.9	3.0

Career

Totalled over the seasons published here, which is not the same as a whole career: a player who debuted before 2005 begins at 2005, not at his real first game.

Career pitching totals. ERA, WHIP and the per-nine rates are recomputed from the components rather than averaged; FIP needs each season’s own constant and is left to the season table.
Statistic	Luis Castillo	Merrill Kelly
G	272	201
GS	266	201
IP	1,541.1	1,170.1
W	88	75
L	95	67
SV	0	0
SO	1,605	1,024
BB	497	370
ERA	3.75	3.93
WHIP	1.20	1.23
K/9	9.4	7.9
BB/9	2.9	2.8
HR/9	1.2	1.2
WAR	25.6	15.1

Luis Castillo’s full profile →Merrill Kelly’s full profile →

More head to heads

The same seasons, measured against somebody else.

Luis Castillo vs

Merrill Kelly vs

How these are computed

FIP uses the constant solved from this season’s own runs, and FIP− is park-adjusted against the same league. dbWAR is our own open implementation — not fWAR or bWAR — and the full derivation, including its simplifications, is on the methodology page. To put these two beside a third, the comparison page takes up to four.