Just look at the number of innings pitched or strike outs versus walks is simple enough. Also, during the 60s the strike zone was beneficial to the pitcher, from the top of the armpit to the bottom of the knee. 1968 was the year of the pitcher, the mound was 2 inches higher on top of it! That year the batting champ(Yastrzemski)won the AL batting title with a .301 average, the lowest in MLB history!
So you can also say that Gibson was fortunate to pitch in a time period when the rules were generous to the pitcher. That does not take away any of his accomplishments though.
Beckett in 2007: 4-0; 30IP(could have pitched more); 35Ks; 2BBs
Gibson in 1968: 2-1; 27IP; 35Ks; 4BBs
For the number of innings pitched, you really can't get much closer! That is pretty dominant by both pitchers, especially by Beckett when you consider the strike zone and height of the mound that Gibson pitched with in 1968.
