Chiefs quarterback Alex Smith had one of the finest playoff performances you’ll ever see from a quarterback on Saturday. Smith, who threw for 378 yards and four touchdowns, with no interceptions and added 57 yards rushing, did exactly what every NFL team hopes its quarterback will do, turning in a brilliant game on a big stage.

But the Chiefs lost, 45-44, which meant that afterward, everyone wanted to talk about one throw that went wrong.

Smith overthrew an open running back Cyrus Gray on a deep ball that would have been a touchdown on the first play of the fourth quarter, one of the key plays that the Chiefs wish they could have back. After the game, Smith said that play was one he and starting running back Jamaal Charles had perfected in practice. Unfortunately, Charles was out of the game with a concussion, and Smith said that when Gray came in to run the play, he was running that route with Smith for the very first time.

“The tough part is all week with so many reps and obviously with Jamaal getting all of those, it’s just something we have never repped with Cyrus, but still got to hit it though. You don’t get many opportunities like that,” Smith said.

Looking at the play, and considering that Charles is faster than Gray, Smith probably threw it exactly where it needed to be if Charles had been the one running the route: Smith’s pass traveled about 30 yards downfield, and Gray was a step or two behind where the ball landed. Charles is probably a step or two faster than Gray on a 30-yard route. If Charles doesn’t get hurt, that play is probably a Chiefs touchdown. Instead, the drive turned into a Chiefs punt.