Getting Started With The Alt Fantasy Optimizer

Users who are not yet familiar with the concept of positive expected value or fantasy optimizer betting should first read our articles on the topics. +EV article can be found here, and the fantasy optimizer article can be found here.

The Alt Fantasy Optimizer operates in a very similar manner as the +EV tool, but with some nuance, which varies from app to app. The name may be a bit unclear, but the tool operates as an optimizer for fantasy markets in which the odds are set for each leg independently, and not based upon the number of legs in a parlay. It is a separate product from the Fantasy Optimizer, and on the odds screen you’ll see separate columns for Underdog and Underdog (Alt) due to how we handle the differing manner of betting. The odds do not change based on the number of legs in a parlay - this is up to you.

These sites are the most straightforward, and operate almost exactly like a sportsbook. In each case, the odds listed on the apps are simply decimal odds and a bet can be placed by simply taking 2 props and including them in a parlay. If the conversion from decimal to american odds is unclear, we offer an odds converter on our calculators page which can be found here.

Betting alternate lines on these sites is not at all straightforward, and must be done carefully. The conversion between listed odds in each site, and implied american odds, is not remotely intuitive.

In the above example, our site lists Underdog’s odds at –141, while Underdog displays a payout of 0.94x. The relation between these 2 values is that a 0.94x payout on Underdog means that whatever the payout would be for that slip type (# of legs) if bets without differing multipliers were included is multiplied by 0.94. For example, a 3-man flex on Underdog has a payout of 6x, so if a 0.94x multiplier were included instead of a base prop, the payout would be 5.6x (+460). Importantly, though the listed Underdog odds is dependent on the slip type (# of legs) in which the prop is being included. A 2-man non-insured has a worse implied odds-per-leg (-136) than a 3-man power (-122), and so if an alt prop (one with a multiplier) is included with a 2-man power, the implied odds are actually worse than if it were included in a 3-man power. When displaying odds on the alt fantasy optimizer, our site assumes that slips are being included using the optimal slip type for that site, which is 6-man insured in the case of Underdog. You can change the slip type from the "Set Slip Type" menu which will change the odds and EV accordingly. You can also do so by using the “Alt Fantasy Multiplier Calculator” found here. After doing so, you may also wish to calculate the EV from the calculator page.

Betr manages to take the cake when it comes to being as confusing as possible with alt-fantasy implied odds. Examples of the types of alt props that Betr offers can be seen in the below image.

Super Boosted: yellow, 3 bars (Stolen Bases)

Boosted: yellow, 2 bars (RBIs)

Mini Boosted: yellow, 1 bar (H+R+R, Runs, Walks)

Edge 1: blue, 1 bar (Total Bases)

Edge 2: blue, 2 bars (Not listed, simply edge 1 but with another filled blue bar)

These alt props show no odds in the Betr app — the only way to see a payout there is to build a slip. We reverse-engineered the payout engine against Betr's own slip validator: a non-insured (Perfect) slip's multiplier is a ladder lookup on "boost points" (each Mini Boosted pick adds 1 point, each Boosted 3, each Super Boosted 5; Edge picks discount the ladder instead), so an alt pick's implied odds depend on the slip around it. The odds we display are each type's best case — ONE alt pick in its optimal Perfect slip size with the remaining legs filled by regular Betr picks from different games: Mini Boosted +128 (1 in a 5-pick), Boosted +256 (1 in a 4-pick), Super Boosted +433 (1 in a 4-pick), Edge 1 -153 (1 in a 6-pick), Edge 2 -198 (1 in a 7-pick), Edge 3 -251 (1 in a 7-pick). A row shows green when its devigged hit rate beats the active type's break-even, meaning it is +EV in that optimal slip.

Two rules to actually capture the listed value. First, Perfect (non-insured) slips only: Betr's flex/insured mode gives alt picks zero extra payout, so an alt pick in a flex slip surrenders its harder line for nothing. Second, one alt pick per slip: stacking several alt picks dilutes the per-pick payout credit on nearly every ladder cell (we verified this exhaustively across all mixed combinations — the best mixes only tie the single-pick optima, never beat them). Use the alt-type pills above the table to pick which type is displayed; each pill shows that type's optimal-slip implied odds.

Same as in +EV explanation, found here.