The NFL's best golden oldies

— -- It's a young man's game, or so we're told. But that doesn't mean some of the older generation aren't still contributing at a high level. In fact, right now in the league, there are 33 players over 35 who have contributed this year, with 17 of those offensive or defensive starters.

That number increases to 54 (with 29 starters) when you look at the age of 34 or over, which is the guys we're focusing on this week -- those golden oldies still getting the job done in what for most is the twilight of their career.

As ever, position grades aren't necessarily cross comparable, but here are the top five players 34 years of age and older based solely on their performance in 2013.

1. Peyton Manning, QB, Broncos: +26.5
Is there any surprise here? Manning had some issues in November after his fantastic start to the year but rebounded in timely fashion when the Broncos needed him to pull them back from the brink against the Chiefs. The oldest man on the list, he's also our top-ranked quarterback regardless of age and third only to Aaron Rodgers and Philip Rivers with an adjusted accuracy percentage of 77.5 percent. He's not the player he once was, but when you're that good, you can drop off and still be something special.

2. Justin Smith, DE, 49ers: +12.9
Although Smith isn't the force he was back in 2011 when he was our defensive player of the year, he's still the type of player you have to account for on every down. His playing time has decreased (he's still playing 78.1 percent of all possible snaps on the year, so he's by no means low) but he's still our sixth-ranked 3-4 defensive end, rushing the passer with 44 quarterback disruptions. Smith is certainly aging gracefully.

3. Dominic Raiola, C, Lions: +11.1
It seemed for some as if Raiola might have been done after finishing a creditable 13th in our center rankings in 2012. Not so, and, with the Lions revamping their offensive line, he has looked rejuvenated playing next to excellent rookie Larry Warford. Raiola might not be as powerful as younger men such as  Manny Ramirez or Chris Myers but he is solid at the point of attack and has the sixth-best pass blocking efficiency of all his peers.

4. James Harrison, LB, Bengals: +10.2
It's easy to forget that the aging Harrison spent the early part of his career on the sideline, and he takes exceptionally good care of himself. So, although his 2012 season was disappointing, there was always the possibility of Harrison finding a role that suited him. Consider that role found as a two-down linebacker in Cincinnati, where the team has reinvented him as a run-stuffing enforcer who might not be getting to the passer much but does remind us of a certain Bart Scott when it comes to blowing up blockers. He has the third-highest grade of all 4-3 outside linebackers against the run and makes life easier for  Vontaze Burfict & Co. -- much as Scott used to for David Harris.

5. Tom Brady, QB, Patriots: +9.6
In another four weeks, Brady will be even higher after an extremely rough start to the year in which he was devoid of his favorite weapons and reliant on some raw rookies. Since the return of Rob Gronkowski, Brady has been back to his usual elite self. His play in the past four weeks has earned him the highest grade of all quarterbacks in that period.

And now our weekly look at the best and worst grades from Week 13, featuring at least one player apiece from defense and offense.

The Best

1. Ndamukong Suh, DT, Lions: +7.2
He does like playing in front of a national audience, doesn't he? Suh got the headlines last year for all the wrong reasons, but this year it was pure dominance. Feasting on an injury-plagued Packers interior line, Suh earned the highest grade of the week with a sack, a hit and four hurries, with the sack resulting in a safety that effectively ended the game.

2. Trent Cole, OLB, Eagles: +7.0
Cole certainly has played well this year, but his pass rush hadn't exactly blown us away. That was until he was lined up opposite Bradley Sowell, where Cole unleashed some frustration with a two-sack, one-hit and five-hurry display that reminded us of the dominant force he once was, and perhaps could be again.

3. Jerome Felton, FB, Vikings: +6.8
After the Vikings' big overtime win against the Bears, the talk was chiefly of the monster day for Adrian Peterson. But how about a little love for the guys who made that possible -- and in particular for Felton, who earned the second-highest grade we've ever given a fullback with his fantastic lead blocking. With just one reception for 5 yards, this grade was all about his seek-and-destroy policy regarding the Bears linebackers.

The Worst

1. Duke Ihenacho, S, Broncos: -5.8
Former undrafted free agent Ihenacho has enjoyed a mixed first season starting, with some good moments outweighed by some bad games. Well, this was the worst of the bunch as the safety missed three tackles and was beaten for a touchdown against the Chiefs. With Denver relatively strong elsewhere on defense, Ihenacho might be the weak link teams continue to exploit.

2. Zane Beadles, LG, Broncos: -5.5
A one-two for the Broncos with Beadles getting the lowest grade of all guards. He didn't help himself by getting beat for a hit and two hurries, but the bulk of his grade was picked up in the run game. Five times he was beaten for a tackle after a short gain (1-3 yards), one time for no gain and another for a loss as Dontari Poe in particular had his number.

3. Donald Butler, ILB, Chargers: -5.3
The year to forget for Butler continued as the Chargers' playoff hopes took a hit against the Bengals. His big problem came when the Bengals frequently got linemen to the second level. On seven occasions, he earned a negative grade, as Andrew Whitworth and friends worked him over. Add in that he was beaten for a touchdown and you have an all-around bad day.