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.
1897 99-63
C Jack Warner 2.45
1B Willie Clark 1.5
2B Kid Gleason 2.4
SS George Davis 6.5
3B Bill Joyce 3.2
LF Ducky Holmes -1.5
CF George Van Haltren 3.15
RF Mike Tiernan 2.35
OF Tom McCreery .55
C Parke Wilson .65
1B Jake Beckley .15
P Amos Rusie 7.6
P Jouett Meekin 4.2
P Cy Seymour 3.95
P Mike Sullivan .2
-Best Giants team of the decade; Rusie returns, he and Davis pace the club.