Julian Edelman was on pace to have a career year in 2015.

He had 61 receptions on 88 targets for 692 yards and 7 touchdowns. His 69 percent catch rate was the second best of his career, his 11.3 yards per reception was the most he's had in a season with at least 10 receptions, and his 7 touchdowns had already topped his career best of 6. The Patriots were rolling and rattled off nine straight wins to start the season.

Everything came back down to earth a bit in Week 10, when Edelman broke a bone in his foot and had to have a screw inserted, sidelining him for the remainder of the regular season. The Patriots slowed down noticeably in that span, closing out the regular season 3-4 but managing to finish second in the AFC.

Edelman made his return last weekend, catching 10 passes for 100 yards in a 27-20 win over the Chiefs, helping the Patriots advance to the AFC Championship Game.

He often gets left out of the discussion of players that make the Patriots' offense what it is (that conversation is typically reserved for Tom Brady and Rob Gronkowski, with Edelman looked at as more of an added bonus), but he has quietly been an absolutely crucial piece of that group.

When Edelman's not on the field, the Patriots perform like an entirely different team, looking nothing like the well-oiled machine they have developed into.

Edelman by the Numbers

Edelman's stats don't tend to jump out like other top receivers because, more than any other top receiver in the league, he does his damage underneath, rarely stretching defenses vertically. The Patriots were the eighth most pass-heavy team in the league this season, with a 1.74 pass-run ratio, and those short quick throws to players like Edelman often take the place of a running game.

That's not to say that Edelman isn't productive. He produced 0.73 Reception Net Expected Points (NEP) per target this season (you can read more about NEP Matt Cassel. Through the first nine games of the season, Brady ranked first among quarterbacks with 100-plus drop backs in Passing NEP per drop back and third in Success Rate.

Though the sample size of games without Edelman in 2014 was much smaller (a full game in Week 16 and half of a game in Week 17), there was a similar trend. Through 14 games, Brady had a 0.24 Passing NEP per drop back, and in the final game and a half actually posted a negative, at -0.11 per drop back.

The difference also shows through in Brady's raw stats. Over the last two seasons, in games Edelman plays, Brady's average stat line is 25.78 for 39.17 (a 65.82% completion rate) for 299.22 yards (7.79 yards per attempt), 2.43 touchdowns and 0.48 interceptions.

Without Edelman those numbers fall to 20.22 for 33.83 (a 59.66% completion rate) for 221 yards (6.5 yards per attempt) with 1.44 touchdowns and 0.56 interceptions. Any way you cut it, the difference is massive.

You might be thinking that the running game picks up the slack, or maybe a difficult schedule skews these numbers (the Patriots did, after all, have to play the vaunted Denver defense in a game without Edelman). But if we look at the numbers for the overall offense, even when adjusted for strength of schedule, we see a huge difference.

Impact on the Offense as a Whole

We've seen now just how much better Brady performs when Edelman is on the field, but let's look at the overall numbers for the Patriots' offense. Here we're looking at the numbers through the first nine games and the numbers by season's end, not simply the Weeks 10-17 split.

Keep in mind, these numbers are per-play and are also adjusted for strength of schedule.

The drop-off is huge. While the rushing numbers are likely impacted by Dion Lewis's injury, that's a big difference in Adjusted Passing NEP per play.

The effect at the end of 2014 was similar, with the Patriots' schedule-adjusted NEP per play falling from 0.15 (3rd in the league) to 0.13 (4th in the league) and the Passing NEP per play going from 0.26 (3rd in the league) to 0.20 (5th in the league) in only two weeks without Edelman.

Edelman doesn't fit the mold when you think of the typical high-impact receivers in the league. He doesn't have the conventional skill set, and he doesn't play a conventional role. But the Patriots aren't a conventional team and don't run a conventional offense. He produces very well in the offense, and his presence is a huge boon for Brady's performance, as well as the performance of the offense as a whole.

He seemed to be back to 100 percent last week against the Chiefs, and that makes the Patriots far more dangerous as Super Bowl contenders than they would be without him.