Best Ball Strategy: Roster Construction for Underdog Fantasy

Ah, so you have this Best Ball thing down to a science?

We’re talking Best Ball all summer long on the Fantasy Footballers DFS & Betting Podcast and as much as we think we can control what happens six months from now, Best Ball starts with a couple of simple principles in mind. None is more valuable than roster construction. You’ve been in the draft room rubbing shoulders waiting for a stack only to get sniped by someone who took their 4th QB. Operating within a structure is like a trampoline… when things are going right and you hit it right, flying high in the air feels incredible. When you come back down to earth, you are glad the frame of the trampoline is there to support you so you can regain your balance.

How many QBs, RBs, WRs, and TEs should we be drafting on Underdog? Let’s dive into each position in detail and take a look at some data* over the last three seasons using Rotoviz’s Underdog Advance Rate Explorer.

Editor’s Note: For Best Ball Rankings and a team-by-team breakdown including pace metrics, stackability, and our highest exposure players, check out the Best Ball Primer included in the Ultimate Draft Kit+.

Quarterbacks

Over the last three years on Underdog, here are the advance rates for QB based on how many total QBs were taken:

On Underdog (and on most platforms), we’re only required to use one QB score each week, so we certainly don’t want to be going overboard on this onesie position, especially when you consider that a lot of the QBs in the 20-32 range (when you’re presumably loading up on these QBs) don’t have true difference-making potential.

Takeaways

You can win with 2 or 3 QBs. If you’re not leaving your draft with 2 or 3 QBs, you’re likely lighting your money on fire. Teams that drafted 1 QB or 4 QBs had the lowest advance rates. If you do take a late QB to pair with an early stud…

• TWO QBs– QB2 after Round 15
• THREE QBs– QB2 in Rounds 14-16 (pretty flat) ideally QB3 after Round 15

The field is definitely on this build, as these two roster constructions were by far the two most heavily utilized builds in last years tourney. However, given how conclusive the data is that this is indeed the optimal way to build, this is not a spot to look for leverage in the tournament.

Injuries Happen. Keep in mind these QBs are not “dead spots” on rosters. The guys you draft late hopefully hold onto the starting job for most of the year. The late round guys often give you access to backdoor stacks. 

Don’t Get Too Cute.  Punting the position, while sometimes viable in redraft leagues, is not advised in best ball. We want to be careful in analyzing data from only one or two seasons, as that’s a very small sample size. However, the opportunity cost in drafting Josh Allen, Patrick Mahomes or Jalen Hurts at or ahead of their ADP is massive relative to the “tier 2 QBs” who are going in the Round 6-9 range. This does not suggest that we should never draft one of the top few QBs in ADP, but this data* at least suggests that we should probably consider the type of players we’re passing on to draft a QB in Round 3 or 4.

Running Backs

Over the last three years on Underdog, here are the advance rates for RB based on how many total RBs were taken:

If you took a couple of RBs early in the first few rounds, it makes sense to assume those RBs will not only stay healthy but perform well. In this example, we probably want to lean more into those RB scores and not waste valuable roster spots on several backup RBs. On the other hand, if you load up on WRs early and avoid the early RBs, it probably makes more sense to try to add more RBs to your roster in the middle and later rounds of the draft in an effort to build with “quantity over quality.”

Takeaways

Draft 5+ RBs. The exact number of RBs to take largely depends on when you take your backs. If passing on the position early, it makes sense to draft more RBs. On the contrary, if you take RB early, it makes sense to draft fewer RBs because we’ll be relying on the scores of our Round 1 and Round 2 RBs most weeks.

Bookmark our Zero RB Targets List. It is possible to draft one elite RB early and do well on Underdog, but drafting multiple RBs prior to Round 7 was been detrimental to advance rates. Drafting your RB2 after Round 7 has historically been a strong bet. the data overwhelmingly agrees that in best ball formats, later-round RBs are crucial to success. With that in mind, we should aggressively be targeting RBs that go in the Round 8 or later range while being mindful of the ones we decide to click in the early rounds.

Opportunity Cost. If drafting RBs early, taking the High T approach and loading up on 3+ RBs early seems counterproductive, likely because you’re passing on the elite WRs available in Rounds 3-5, which we know historically have massive upside.

How often Zero RB, Hero RB, Robust RB were drafted in Best Ball Mania IV. pic.twitter.com/myIRZNxVPX

— Hayden Winks (@HaydenWinks) May 20, 2024

Wide Receivers

Over the last three years on Underdog, here are the advance rates for WR based on how many total WRs were taken:

On Underdog, we’re required to use 3 WR scores every week, and ideally, we want to be using a WR score in the flex given that WR variance is associated with higher win rates. So, in an ideal scenario, we want to be using 4 WR scores every week if possible. This starting lineup requirement alone tells us that we need several WRs on our best ball rosters. Not surprisingly, the data agrees.

Takeaways

Draft 4+ WRs before Round 8. Despite the notion that we can just make up for a lack of quality with quantity at WR, the data suggests we should be leaving the first few rounds with multiple WRs. Robust RB builds struggled, likely because those teams lack an elite WR that actually has meaningful upside that the double-digit round WRs simply don’t have.

Build with the End in Mind. We want to “work backwards” knowing the WRs at the end of the draft are often dust. Some don’t even crack an NFL roster so the idea of adding 2-3 WRs in the final five rounds is wishful thinking. You should be shooting for 7+ WRs but six of them should be on your roster by Round 13.

Rookie WRs are a good investment. I wrote Rookie WRs & Riding the Summer Wave of ADP in early May. Dating back to the famed 2014 class, we’ve averaged 3.7 “impact” rookie WRs per season to finish as top-36 fantasy WRs. Top-36 might not sound so enticing to you except when you consider the best ball format and its present content. We’re never getting back to the glory days of finding rookie WRs super late. Drafting earlier in Best Ball (May, June) gets you values on rookie WRs. We are likely too overconfident in some of these rookies contributing… BUT when they hit, they are massive difference-makers.

Tight Ends

Over the last three years on Underdog, here are the advance rates for TE based on how many total TEs were taken:

Takeaways

2-3 TEs. In most scenarios, if you draft one TE early, you likely only need 2 TEs. On the other hand, if you pass on TE in the first 5 rounds, 3TE builds seem to be optimal. Drafting a TE early is admitting that their score will be one you use 7%% of the time. Remember we care about “points added” for Best Ball. TEs don’t have the same ceilings as other positions and thus having spike weeks is more an added bonus. Consistent scorers like Evan Engram are often underrated.

Tight End is a complete clown show. Thanks to being the least they’ve been involved in the red zone in years, we need to tell you a simple secret: no one really knows how TEs work. Use the overconfidence of what the field assumes is correct against them as leverage in large tournaments.

Bullies Get Into Trouble. The “bully TE” strategy sounds like a fun strategy, but the advance rates are terrible when selecting 2 TEs before Round 7. Those teams advanced to the playoffs just 10.2% of the time, well below our advance rate of 18% for teams that drafted 3TEs last year or teams that drafted 2TEs but didn’t take 2 TEs early (table above). It is not a common strategy among teams making it to Best Ball Mania finals.