THIS sounds familiar.

Why were the Colts so bad when passing with a 4th quarter lead? First, we need to understand the Colts were primarily a 11 personnel team when passing, which means 3 WRs. When passing, they used 3 WRs approximately 79% of the time and 2 or fewer WRs 21% of the time.

The Colts were substantially more efficient when passing from 2 or fewer WR sets.
When using 3 WRs on the season, they were successful on 43% of passes, delivered an 82 rating and averaged 6.8 YPA.
When using 2 or fewer WRs, they delivered a 52% success rate, with a 91 rating and 7.8 YPA.

They needed a good self scout.