What Is the Flex Position in Fantasy Football and How Do You Use It?
The flex position is a roster spot that accepts players from multiple positions. Instead of requiring a specific position like a dedicated RB2 or WR3 slot, the flex spot lets you choose which position to prioritize each week based on matchups, injuries, and available production.
Flex Position Quick Reference
| Format | Who is eligible for flex | What it changes |
|---|---|---|
| Standard RB/WR/TE flex | Any RB, WR, or TE | Most common; gives full flexibility to start your best remaining skill player |
| WR/TE only flex | Only WR or TE | Less common; increases TE value by putting TE in direct competition with WRs for a starting spot |
| RB/WR only flex | Only RB or WR | Decreases TE value compared to standard — TEs cannot use the flex to get a second starting slot |
| Superflex (QB/RB/WR/TE) | QB allowed in flex | Dramatically increases QB value — effectively a 2-QB format; changes draft strategy entirely |
How the Flex Position Works
In a standard fantasy league, your starting lineup might look like: QB × 1, RB × 2, WR × 2, TE × 1, FLEX (RB/WR/TE) × 1, K × 1, DEF × 1.
The FLEX slot accepts any eligible player — RB, WR, or TE — and each week you choose which player to start there based on who you expect to score the most.
Why the flex exists: Fantasy rosters reflect NFL positional realities. NFL teams use different numbers of running backs and receivers depending on their offensive scheme. The flex lets your fantasy team reflect that flexibility — you can adapt your lineup based on who is healthy, who has a favorable matchup, and which positions are stronger on your roster in any given week.
How to Use Your Flex Spot
Start your third-best skill position player. The flex spot is simply your third-highest scoring eligible player each week. If your RBs and WRs are set, look at your remaining RBs, WRs, and TEs and start the one with the best projected score.
Exploit matchups. If your WR bench has a player going against a weak secondary, flex them instead of an RB facing a top-tier run defense.
Injury adjustments. When a RB2 or WR2 gets hurt, the flex spot is often where you compensate. If your RB2 is out, you might flex a backup RB from the waiver wire, or start an additional WR if your receivers are deeper.
Weekly decision order. The flex decision is often the last lineup decision you make each week because it depends on who you are already starting at the dedicated slots. Once you set RB1, RB2, WR1, WR2, the flex is a competition between your remaining eligible players.
What the Flex Means for Draft Strategy
Value of RB and WR depth: Since the flex spot can be RB or WR, building depth at both positions pays off. A team with three strong RBs can start two at the dedicated spots and flex the third. A team with strong WR depth does the same at WR.
TE value in the flex: In a standard RB/WR/TE flex league, TEs can start at either the dedicated TE slot or the flex. This is mostly theoretical since most managers prefer to start an RB or WR in the flex — TEs have lower average scoring than RBs and WRs except at the very top of the position. But an elite TE who is the best available skill player on your bench any given week should flex.
Superflex changes everything. In superflex leagues, the flex becomes a second QB slot — this is covered in a dedicated guide on the superflex format.
Common Flex Mistakes
Forgetting to set it. The most basic mistake — leaving the flex empty when you have eligible players. Always check all positions before the lineup lock.
Defaulting to RB. Many newer players always put an RB in the flex because it “feels right.” The flex decision should be based on projected points, not habit. A WR with a great matchup should start over an RB in a committee situation.
Ignoring the flex in draft strategy. The flex spot means your roster needs three quality skill position players who can contribute at the starter level. Drafting only two strong RBs and two strong WRs leaves you relying on your 5th RB or 5th WR as a flex starter — a weak position.
For how the flex interacts with the rest of your starting lineup, see: How Fantasy Football Works: The Complete Beginner’s Guide. For the superflex variant that turns the flex into a QB slot, see: What Is Superflex Fantasy Football?.