It should be obvious to anyone who has seen the Cleveland Indians play this year that there is something special going on with the starting rotation. As a team, the Indians are currently best in the Majors with 14 shut outs, a number largely aided by the starters being able to go deep into games. It has been a long time since the Indians have had starting pitching this good, so it seems necessary to look at the 2013 team in a historical prospective.
Looking back at every Indians starting rotation in team history (starting in 1901), we find the greatest ERA in team history occured in 1908 when Addie Joss lead the starting five (the top five starters were considered for every season, irrelevant if they used a four or five man rotation) to a staff ERA of 1.75. This is more interesting trivia than actual comparison as changes in the game have made such a season impossible at the present date.
Removing all teams that had a staff ERA above 3.75 leaves three teams since 1980, including the 2013 staff with an ERA of 3.67 through 98 starts (and 112 total games). The other two teams that stand out are the 1991 and the 1989 squads. The active rotation currently stands above these other two with a better winning percent, batting average against and a significantly better K/9. The K/9 is really where this team stands out. Only eight rotations in Indians history have ended a season with a K/9 above 7.00 and the current group holds one of 8.34. This is largely to do with Scott Kazmir, who ranks 19th in MLB history in the stat and has struck out 100 batters in 111 innings as of August 6th. Two players that have been on the team for a few seasons (Justin Masterson and Corey Kluber) are also having career years in strike outs, helping this team outpace the past few seasons. If they continue this pace, they will set a new record for K/9 for the regular starting five, surpassing the 2000 rotation that featured such super stars as Jason Bere and Jim Brower (but set the record because of Bartolo Colon).
Going past the 1980's, the 2013 outperformed a few more teams in overall greatness, beating every team until 1972 in BAA and all but two in ERA. The 1972 team, however is an unbeatable stopping block as it housed the Indians first Cy Young Award winner, Gaylord Perry, along with great seasons by Dick Tidrow and Milt Wilcox. These three (who got the majority of the starts) combined for an ERA of 2.51, a BAA of .213, but just a 45-45 record as the Indians were deep into their nonexistent offense years. The numbers for each team with a staff ERA below 3.75 are listed below so you can judge for yourself, but right now it looks like the current rotation is the Indians best since that 1972 team.
One interesting note is that many of these teams did not finish the season very well, with none of them reaching the playoffs and two finishing below .500. That is the biggest difference between the current roster and that of those ineffectual teams. While the 1970's teams had light hitting infielders, like Jack Brohamer and Frank Duffy, the 2013 team has Jason Kipnis and Asdrubal Cabrera. In total, the 1972 starting eight hit 58 home runs and knocked in 303 runs, while the current starting eight (including Reynolds as the third baseman with no DH) has hit 79 home runs with 362 RBI and has a third of the season yet to play. That amazing 1972 team finished the season the season 72-84 and in fifth place in the AL East. The current team is second in the AL Central and first in the race for the second Wild Card place. While having a strong starting five is incredibly important to keeping the other team off the board, apparently there is a little more to the sport than "pitching, pitching, pitching."
The resurgance of Scott Kazmir has helped the Indians rotation return to the days of old.