Bingo! Jim Plunkett was teriffic at Stanford winning the 1970 Heisman Trophy. He won two Super Bowls with the Raiders as starting QB and was the Super Bowl MVP in one of those games.
If Plunkett was the worst Patriot QB,the team should have a dozen or so perennial All Pro QBs in its history. Last time I checked, the Pats were about 10 QBs short of a dozen.
If you saw Joe Kapp play, there is no doubt he was atrocious.
To illustrate this ignominious claim: in a game in KC, Joe Kapp threw an interception on three consecutive plays. One was fumbled back and a second was negated by penalty. Nonetheless, Kapp threw three interceptions in a real time span of about 90 seconds. Read that last sentence again.
Kapp was a disaster off the field as well. After leading the Pats to the NFL's worst record, Kapp was to mentor just drafted QB Jim Plunkett. A month before training camp, Kapp abruptly quit resulting in the rookie have to start in his first game in the NFL (a huge upset win over the powerful Raiders).
Joe "Duck" Kapp was was a terrible QB who suffered great difficulty in throwing a spiral. You know, like the third string QB on your local high school junior varsity. His arm was that bad.
No hesitation, Joe Kapp was the worst Patriot QB.
Joe Krapp, indeed.