By most accounts, Bucs tight end O.J. Howard had a promising rookie season. He caught six touchdown passes, which set a Bucs rookie record and was one short of the NFL high among rookies at any position.Pro Football Focus, in handing out grades to all 32 first-round picks for their 2017 seasons, gave Howard the lowest grade out of all 32.We readily concede that it's a difficult and extremely subjective thing to assess a numeric value to a player's season — different positions, different amounts of playing time, wildly different circumstances and so on.And playing tight end well is far more than just catching passes — but even if Howard were deemed a below-average blocker, surely 26 catches for 432 yards can offset that a bit, right? Howard lost two fumbles, and that should count against him as well.But Howard's grade — a 41.9 out of 100 — is even lower than Bengals receiver John Ross, who was picked ninth overall, and barely played as a rookie. He was only active for three games, did not catch any passes, and his lone touch of the season, a 12-yard carry, resulted in a fumble recovered by the opponent. He played just 17 snaps all season before going on injured reserve with a month to play — and is graded higher than a player who scored six touchdowns.Now if everyone sees PFF's grades and says "that seems about right," there aren't nearly as many people talking about them as if there seem to be snubs and social-media outrage and blog posts like this.Consider another direct comparison: Chiefs QB Pat Mahomes, who went 10th overall, and Texans QB Deshaun Watson, who went 12th.Mahomes played in a single game — in Week 17 as the Chiefs rested starter Alex Smith — and did not throw a touchdown pass, had an interception and went 22-of-35 for 284 yards.Watson played in seven games before a season-ending injury, threw for 19 touchdowns — that pro-rates to 43 over 16 games — with only eight interceptions. His passer rating was a 103.0, third-best in the NFL among all passers with 50-plus passes, better than Tom Brady and Carson Wentz.PFF gave Mahomes a 79.9 rating and Watson a 75.1 rating.Even if you're grading on technique rather than production — you can run a bad route and still catch a touchdown; you can have great pass coverage and still give up a score, etc. — it's hard to justify some of these scores.We talked to Howard after the season and he admitted he has areas to work on as he prepares for his second year in the NFL. With luck, maybe he won't get the worst grade in his class in 2018.