As I recall SB X, Roger did not have the kind of day he was accustomed to. Out of 82 QB SB performances, I'd say number 50 is about right for that particular day. It was not his best day for sure, but the Steel Curtain had a lot to say about that.
You notice he is also in the top 20 for losing QBs (SB XIII.)
Now that was a great game that went down to the wire. One of the top 2 or 3 SBs ever, IMHO.
Who knows what would have happened if Jackie Smith had caught that pass. I was a kid of 8 when that game was played but I still remember it as one of my favorites.
...and I thank God that Smith dropped it.