Last week I discussed a trend that's changed the way running backs are played and viewed in fantasy football. I thought it was a pretty good analysis, if I do say so myself.

And while I was busy patting myself on the back last weekend, I realized I've been an idiot by completely missing another running back trend. This one was pretty obvious, but I've missed the boat for a couple years now. It's definitely cost me points, wins and maybe even titles.

So let's get it out in the open so that fate doesn't happen to you.

For years, the great running backs would play most of their career with one team. Sometimes they even retired with that team. But when they moved on, it was in the twilight of their career and they became a shadow of their former selves while wearing a different helmet.

Hall-of-Famer Tony Dorsett left the Cowboys and finished his career in Denver. LaDainian Tomlinson went to the New York Jets. Emmitt Smith played for the Arizona Cardinals. Eddie George went to Dallas. Earl Campbell went to New Orleans. And I've heard a rumor that Thurman Thomas put on a Dolphins uniform, but I still don't really believe it.

In all of those cases, they weren't the same player on the new team. There were a couple of decent seasons here and there, but for the most part those guys were finished. That goes double for any fantasy football contributions. And for me, that was the end of the story. If a running back left their longtime team, I ignored them on draft day. I didn't just downgrade them, or put an asterisk by their name. I didn't even consider them. No disappointments and no headaches for me.

And for a while, that was smart. But when the game changed, I didn't. And being stubborn has cost me a shot at some pretty productive players. If there were hints of that in the past, it's crystal clear in 2016.

In my mind, DeMarco Murray was done when he cashed out from a couple of strong seasons in Dallas and went to Philadelphia. When he moved again to Tennessee, it was clear that a wise fantasy player would avoid him. He was now two teams removed from fantasy relevancy.

All he's done this season is crack the top five in rushing yards. Technically, after the early Thursday game, he leads the league in rushing. He's on pace for a 1,500-yard season, 16 total touchdowns and even 56 catches if you're a PPR fan. But if I just missed on DeMarco Murray, I could probably forgive myself and move on. If only it was that simple.

LeSean McCoy was winding his career down when he moved to Buffalo. Why bother with that headache on draft day? Well, how about another top-five rushing performance through the first seven games? He's averaging north of five yards per carry and a score per game. Even with his hamstring issues, he's proven to be a valuable asset for his team and many fantasy squads. Not mine, of course. But plenty of others.

Matt Forte? Frank Gore? They're not setting the world on fire, but they're helping fantasy football teams win games. They certainly didn't deserve to be ignored on draft day. So what's going on?

Once again, it comes down to that special something that keeps the league going: Money. Teams are managing the salary cap in shrewd ways, and hope to save the cash that would have gone toward a big pay raise for their running backs. That means star players aren't necessarily limping toward retirement when they switch teams. They're sprinting toward a paycheck.

And thanks to advancements in nutrition and sports medicine (as well as a smarter use of on-field talent), a player's career can last longer than they did in the past. Murray and McCoy are 28, and Forte is 30. Gore is 33 and productive. While nobody expects players to be effective well into their 30s, approaching 30 isn't the red flag it used to be.

So while I missed this trend for a while, I also realized that missing trends is, in itself, a trend. What I mean is, you can't get so stuck in your philosophies that the game passes you by. You can't be the last owner to realize that RB-RB isn't the only draft strategy. You can't assume that "ignore the top quarterbacks and pick value later" is going to be true for as long as you play fantasy football. And don't convince yourself that a running back on a new team is a wasted draft pick. Even if they have some wear on their tires.

Now, don't get me wrong. These oversights don't have to be fatal mistakes. My teams don't have any of those running backs, and they're all in good shape halfway through the fantasy season. But my teams don't need an owner who's stuck in a philosophy that doesn't necessarily apply anymore. And neither do yours. Make sure that you keep an open mind each season, and that includes during the season. You still have time to make trades, use the waiver wire and improve your team. Keep all your options open. Good luck this week.

Are you having success with older running backs? Are you finding that some of your tried-and-true philosophies don't always apply anymore? Share your thoughts below.