My WAR calculation is a combination of Baseball-reference and Clay Davenport; I believe it to be the "best" WAR number available for historical comparison. 8 WAR is an MVP quality season. The record is pythagorean adjusted for 162 games.
1909 91-63
C Admiral Schlei 2.15
1B Fred Tenney 1.3
2B Larry Doyle 3.05
SS Al Bridwell 4.5
3B Art Devlin 4.05
LF Red Murray 1.9
CF Bill O’Hara .9
RF Moose McCormick 1.75
OF Cy Seymour 2.4
1B Fred Merkle -1.5
C Chief Meyers 1.9
OF Buck Herzog -1.05
Ut Tillie Shaffer -.45
Ut Tillie Shaffer -.45
SS Art Fletcher -.8
SP Christy Mathewson 10.65 MVPQ
SP Bugs Raymond 3.35
SP Hooks Wiltse 4.55
SP Red Ames -.1
SP Rube Marquard -.35
RP Doc Crandall .15
-McGraw's worst of his 7 Giants teams, still wins 90+ pythagorean games.