Fantasy Football
Beginner Guide to Flex Positions
A beginner-friendly guide explaining what flex positions are, the different types of flex spots, and how to make the most of your lineup every week.
What is a flex position?
A flex position is a lineup spot that allows you to start players from more than one position.
Instead of requiring a specific position like quarterback or running back, a flex spot gives you the flexibility to choose from multiple eligible positions.
For example, a standard flex may allow you to start:
Running Back (RB) Wide Receiver (WR) Tight End (TE)
This gives managers more lineup options each week and makes roster construction much more strategic.
Position-specific spots vs. flex spots
Every fantasy lineup is made up of two types of roster positions.
Position-specific spots
These positions can only be filled by one position.
For example:
QB RB WR TE K D/ST
If your lineup has one quarterback slot, only a quarterback can be started there.
You cannot move another position into that spot.
Flex spots
Flex positions allow multiple positions to qualify.
For example:
FLEX
RB ✅ WR ✅ TE ✅
You choose whichever eligible player gives your team the best chance to score points that week.
Why do fantasy leagues use flex positions?
Flex positions make fantasy football more strategic.
Instead of forcing every team into the exact same lineup, managers can build their roster around their strengths.
For example:
One team may have three excellent wide receivers.
Another may have four strong running backs.
A flex spot allows both managers to start their best available players without being limited by strict positional requirements.
Standard FLEX
The most common flex position is simply called FLEX.
It usually allows managers to start:
Running Back Wide Receiver Tight End
This is sometimes abbreviated as:
RB/WR/TE
This is by far the most common flex position in fantasy football.
Superflex
A Superflex expands the eligible positions even further.
Managers may usually start:
Quarterback Running Back Wide Receiver Tight End
Because quarterbacks generally score more fantasy points than other positions, most managers choose to start a second quarterback whenever possible.
This dramatically increases quarterback value compared to traditional leagues.
WR/TE Flex
Some leagues use a position-specific flex.
For example:
WR/TE
This means you may start:
Wide Receiver Tight End
Running backs are not eligible.
This type of flex slightly increases the value of wide receivers and tight ends while limiting roster flexibility.
RB/WR Flex
Another common variation is:
RB/WR
Managers may start:
Running Back Wide Receiver
Tight ends are not eligible.
Offensive Player (OP)
Some leagues include an Offensive Player (OP) position.
This typically allows:
QB RB WR TE
Unlike Superflex, some platforms may have slight differences in eligibility, so always check your league settings.
IDP Flex
Individual Defensive Player (IDP) leagues sometimes include defensive flex positions.
Examples include:
DL/LB LB/DB Any Defensive Player
Instead of locking managers into one defensive position, IDP flex spots provide more lineup flexibility on the defensive side of the ball.
Multiple flex positions
Many fantasy leagues use more than one flex spot.
For example:
2 RB 2 WR 1 TE 2 FLEX
This gives managers even more lineup flexibility.
If your roster is especially deep at one position, multiple flex spots allow you to maximize that depth.
Choosing who to start in your flex
One of the biggest beginner mistakes is treating the flex as an afterthought.
Your flex should simply be the highest-scoring eligible player who isn't already in your lineup.
Ask yourself:
Which player has the best opportunity? Who has the safest workload? Which matchup is most favorable? Who gives my team the highest scoring potential?
Don't think of the flex as a "backup" position.
It's another starting position that deserves just as much attention.
A common flex example
Imagine your lineup looks like this:
RB1 RB2 WR1 WR2 TE FLEX
Your roster includes:
3 starting-caliber running backs. 2 starting wide receivers. 1 tight end.
Since your two required running back spots are already filled, your third running back can be started in the FLEX.
Likewise, if your third wide receiver projects to score more than your extra running back, you can use the flex on the receiver instead.
The goal is always to start the player expected to score the most fantasy points.
Save your flex for later kickoff games
One strategy many experienced managers use is leaving a player with a later kickoff time in the FLEX position whenever possible.
For example:
Instead of:
FLEX: Sunday 1:00 PM Running Back WR: Sunday Night Wide Receiver
Many managers prefer:
WR: Sunday 1:00 PM Wide Receiver FLEX: Sunday Night Running Back
Why?
If unexpected injury news breaks before Sunday night, you'll have more flexibility.
Since the FLEX accepts multiple positions, you can pivot to another running back, wide receiver, or tight end if needed.
If your late-game player is locked into a position-specific slot, your replacement options become much more limited.
It's a small strategy, but one that can occasionally save your week.
Flex value changes by league
The more flex positions your league has, the more valuable overall roster depth becomes.
For example:
A league with:
2 RB 2 WR 1 FLEX
places less emphasis on depth than a league with:
2 RB 3 WR 2 FLEX
More starting spots mean more players contribute to your weekly score.
That often increases the value of quality depth throughout your roster.
Beginner mistakes to avoid Do not treat the flex as your "leftover" position. Do not automatically start a running back in the flex every week. Do not ignore favorable matchups when choosing your flex player. Do not forget to check which positions are actually eligible in your league. Do not overlook the flexibility of placing later kickoff players in your FLEX spot. Do not assume every league uses the same type of flex position. How Legacy Social helps
Legacy Social helps fantasy managers make better lineup decisions by bringing player rankings, matchup discussions, community polls, and start/sit advice together in one place.
Whether you're deciding between a running back and wide receiver for your FLEX spot or trying to determine the best Superflex option, Legacy Social gives managers the tools and community insights needed to maximize every lineup position. As additional league integrations continue to expand, personalized lineup analysis and roster insights will provide even more context for making confident weekly flex decisions.