Accuracy is a hard thing to quantify for quarterbacks. Completion percentage is flawed for several reasons. It doesn’t take into account throwaways, accurate passes batted away by defenders and the difficulty of throws a quarterback makes based on the scheme he plays in.

You can’t really judge a quarterback’s accuracy without watching him play. Well, Pro Football Focus watches every snap of every game, and that allowed them to release a new stat this week that tells us which NFL quarterbacks are the most precise.

“Accurate+ %” measures what percentage of a quarterbacks throws hit the intended receiver right in stride — in other words, a perfect throw. Using the stat, let’s take a look the most and least precise starters in the league.

Note: We’re only including QBs who are expected to start for their teams in 2018. Arizona’s Sam Bradford did not make enough throws in 2017 to qualify, giving us a list of 31 quarterbacks.

Most precise

1. Tom Brady 24.2%

2. Philip Rivers 22.6%

3. Jimmy Garoppolo 22.5%

4. Drew Brees 22.3

5. Carson Wentz 22.1%

Brady, Rivers and Brees have been among the most accurate quarterbacks in the league for over a decade now. No surprises there. It is somewhat surprising to see Garoppolo crack the top three, but there’s some sample size concerns with him, obviously. Wentz may have been the biggest boom-or-bust QB in the league last year. While he ranked fifth in “Accuracte +” throws, he ranked 32nd in avoiding uncatchable throws.

Least precise

27. Mitchell Trubisky 13.4%

28. Case Keenum 12.6%

29. Kirk Cousins 12.3%

30. Derek Carr 10.4%

31. Deshaun Watson 10.3%

Now, this is a surprising list. Trubisky didn’t have a great season, so his percentage won’t raise any eyebrows, but the Bears rookie ranked ahead of two of the highest-paid quarterbacks in the league (Carr and Cousins), a prized free agent (Keenum) and the favorite to win rookie of the year at the time of his injury (Watson).

You can see where the rest of the other quarterbacks rank by checking out PFF’s 2018 QB Annual…