Head to head · 2025 pitching

Spencer Arrighetti vs Hayden Birdsong

In 2025 Hayden Birdsong has been worth 0.1 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.

Spencer Arrighetti HOU

Hayden Birdsong SF

2025 pitching. The stronger figure in each row is highlighted — for ERA, FIP, WHIP and walks that is the lower one.
Statistic	Spencer Arrighetti	Hayden Birdsong
G	7	21
GS	7	10
IP	35.1	65.2
W	1	4
SO	31	68
ERA	5.35	4.80
FIP	5.54	4.96
WHIP	1.42	1.49
K/9	7.9	9.3
BB/9	5.1	5.1
FIP−	133	119
WAR	-0.1	-0.0

Career

Totalled over the seasons published here, which is not the same as a whole career: a player who debuted before 2015 begins at 2015, 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 table above.
Statistic	Spencer Arrighetti	Hayden Birdsong
G	59	37
GS	54	26
IP	288.2	137.2
W	16	9
L	27	10
SV	0	0
SO	306	156
BB	147	80
ERA	4.77	4.77
WHIP	1.40	1.44
K/9	9.5	10.2
BB/9	4.6	5.2
HR/9	1.4	1.4
WAR	1.2	0.3

Spencer Arrighetti’s full profile →Hayden Birdsong’s full profile →

More head to heads

The same seasons, measured against somebody else.

Spencer Arrighetti vs

Hayden Birdsong 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.