Dynasty leagues offer a fun twist of fantasy football in which owners retain most, if not all of their players from year to year. This creates a greater sense of pride and ownership as you carry many of the same players for multiple seasons.

Of course, you've got to make sure you have a core of players you actually want to carry for years and years. If you end up with a roster saddled with aging, injured veterans and young, inconsistent newcomers, your roster will lean more toward "rebuilding" than "dynasty." That's where the initial startup draft comes into play.

Twelve of RotoBaller's finest contributors gathered for a dynasty startup mock draft. Over the next week, we'll break it down round-by-round, continuing with the fourth, fifth and sixth rounds in this article. Check out our earlier recaps of round one, and rounds 2-3 to see how this draft progressed.

Round 4

Incoming rookies were popular in the fourth round. Smith-Schuster, Davis and Fournette marked the first three picks of the round, with Williams coming later on. Much like in the actual NFL, rookies are unknown commodities. There's significant risk, but also significant upside, particularly in a dynasty league, where youth and potential are valuable assets.

This round also featured plenty of familiar names from the fantasy world, including LeSean McCoy, Aaron Rodgers, Derek Carr and Lamar Miller. Terrelle Pryor parlayed his breakout season with the Browns into a one-year deal with Washington, a move that boosts his fantasy value. Alshon Jeffery's move to Philadelphia hurts Jordan Matthews' value.

Rodgers and Carr were the first two quarterbacks off the board, while Hunter Henry and Travis Kelce were the third and fourth tight ends selected, respectively. This was the most balanced round, with five wide receivers, three running backs, two quarterbacks and two tight ends taken.

Round 5

Wideouts, wideouts, wideouts. The fifth round was heavy on veteran pass-catchers and, unlike the previous round, featured no incoming rookies. Sterling Shepard's selection kicked off a run of five straight wide receivers to open the round.

Tate, Edelman and Crabtree are all proven, if aging, commodities, while Shepard, Hill and Crowder are promising young players. Josh Doctson is a wild card, but he's still young enough to carry value.

Four running backs (Prosise, Coleman, Hyde, Henry) and one quarterback (Luck) also went in the fifth round. No major surprises among that group -- all are in their 20s and have promising careers ahead.

Round 6

Back to the incoming rookies! McCaffrey and Mixon led off the sixth round, with Ross coming just two picks later. This round featured a decent number of proven veteran performers, including DeMarco Murray, Emmanuel Sanders, Cam Newton and Randall Cobb.

Britt, like Pryor, also changed teams in the offseason, but it's difficult to get excited about his move to Cleveland. Tyler Eifert (injuries) and Martavis Bryant (suspension) are intriguing picks, as is Rishard Matthews, who finished with nine touchdown receptions last season.

Overall, the sixth round featured six wide receivers, four running backs, one quarterback and one tight end.

Best Picks

Leonard Fournette (RB, LSU) #39 overall

Fournette's value is going to depend on his landing spot in April's draft. If he ends up somewhere like, say, Carolina, that figures to boost his value. If he lands with a team like the New York Jets, well ... that won't boost his value.

Given the immediate rookie success of Ezekiel Elliott this past season, Fournette is sure to be a popular pick in most fantasy drafts. But that's particularly true in a dynasty league, where you can control him for years to come. At 39th overall, I like the value.

Tevin Coleman (RB, ATL) #55 overall

Coleman showed this past season that he can provide serious fantasy value while splitting the backfield touches with Devonta Freeman. Coleman will be 24 at the start of the 2017 season, which could be Freeman's last in Atlanta, if he ends up leaving as a free agent.

If that were to happen, Coleman's value would skyrocket as the primary back in Atlanta's offense. If Freeman stays, then maybe Coleman leaves for a starting job elsewhere after 2018. Or perhaps the two remain a productive tandem in Atlanta. No matter what, landing a dynamic, 24-year-old running back with the 55th pick is a win-win.

Cam Newton (QB, CAR) #71 overall

It was an ugly season for Newton in 2016. And, yet, his season wasn't actually that bad. The expectations for Newton coming off his historic MVP season in 2015 were sky-high, so it's not shocking he suffered from regression.

He's a prime bounce-back candidate in 2017 and beyond. Newton, despite playing six seasons in the NFL, will only be 28 when the upcoming season begins. He still boasts elite rushing ability, which further adds to his fantasy value. He's a solid pick as the fourth quarterback (and 71st player overall) off the board.

Biggest Reaches

JuJu Smith-Schuster (WR, USC) #37 overall

I'll say it again -- drafting rookies is an inexact science. Smith-Schuster certainly could become a great NFL wide receiver. But is worth a top-40 overall pick? It's difficult to support that decision. He was the first rookie wideout selected, ahead of guys like Davis, Williams and Ross, among others that have similar, if not higher, consensus grades.

Also, when's the last time a USC wide receiver excelled for an extended period of time in the NFL? I'll wait... The answer? Keyshawn Johnson. That's not totally fair to Smith-Schuster, who could end up being great, but it's worth noting nonetheless.

Joe Mixon (RB, OKLA) #62 overall

This is a pick that is sure to draw some attention. If Mixon had no off-field issues, this would be a fine selection. But Mixon carries serious baggage stemming from a 2014 assault incident. That baggage is so heavy, in fact, that it kept him from participating in the NFL scouting combine.

Mixon performed well at Oklahoma's pro day, but there's still some major question marks. Will he slip in the draft, and if so, how far? Will he able to avoid trouble in the NFL? Will he be worth the 62nd overall pick in this mock draft? The answers to all of those questions remain unclear.

Kenny Britt (WR, CLE) #67 overall

I must admit, I wasn't a big fan of this selection when Britt was still with the Los Angeles Rams. Now that he's with Cleveland, I like it even less. It's a total head-scratcher for Britt, who has played with a series of underwhelming quarterbacks in his eight-year career with Tennessee and Los Angeles.

Now, he finally has a choice to choose his team in free agency, and he settles on Cleveland and ... Cody Kessler? Kevin Hogan? Someone else? Sure, maybe Cleveland lands Jimmy Garoppolo, Britt becomes a go-to target and this pick turns into a steal. But for now, I'm going to assume the Browns remain a fantasy wasteland.

Conclusion

Let's take a closer look at the numbers. Of the 36 players selected in the fourth, fifth and sixth rounds of RotoBaller's dynasty startup mock draft, 18 were wide receivers, 11 were running backs, four were quarterbacks and three were tight ends. There were seven incoming rookies selected, compared to just three players who will be 30 or older at the start of the 2017 season (Rodgers, Edelman, Sanders).

That latter statistic isn't entirely surprising for a dynasty mock draft. When building a roster for the long haul, it's ideal to have players that will provide value not only for the immediate season, but future seasons to come.

Free agency is barely a week old, and the NFL draft is still more than a month away, so a lot can change between now and the regular-season opener on Sept. 7. But hey, who doesn't love a good mock draft?

Be sure to follow along with the rest of our round-by-round analysis throughout the week.

More 2017 Mock Drafts & Analysis