Captured from the MOTA tab inside app.muchomota.com. One $50K bankroll, one 1.10 markup, three ACR Standard $215s at fields of 100, 1,000, and 2,500. The Kelly-optimal sell % per cell shifts under your feet as the field grows.
$50,000 bankroll. Sitting down to an ACR Standard $215. A buyer offers 1.10. How much do you sell?
You get the whole map. Each cell is a skill hypothesis — rows are CF (cashing-frequency archetype), columns are HU (heads-up). Color is the Kelly-optimal sell fraction at 1.10. Number is your ROI under that hypothesis.
Green — keep more. 1.10 underprices your edge. Gold — sell more. The markup pays for the variance you shed. Red — sell 100%. Either ROI is negative, or it’s positive but the bankroll can’t carry the variance at this size.
Read the three figures together. The cells don’t move. The colors do.
Shallow payout, contained variance. Anywhere in the upper half of the (CF, HU) cloud, 1.10 underprices the edge. Keep skin in. The red strip across the bottom is the answer you’d give without a model: negative ROI, take the markup.
Ten times the field, roughly ten times the top-prize multiple, σ² up sharply. Kelly punishes that geometrically. The keep-region survives only at the strongest skill hypotheses; everything else flips to sell-100%. The same edge that was worth holding in the 100 now pays better as markup than as hold.
By 2,500 runners the answer collapses. Sell-100% covers nearly every (CF, HU) hypothesis at this bankroll and this markup. The markup is the trade. The tournament isn’t.
EV ranks all three the same — at fixed skill, ROI per cell barely moves with field. Kelly disagrees because Kelly maximises E[log W], not E[W]. A 2,500-runner has a fatter right tail and heavier left mass, and the geometric growth rate sits below the arithmetic mean by ½σ². Holding above the Kelly-optimal sell isn’t a blowup — it’s a strictly slower compounding curve. The heatmap prices that gap cell by cell.
Open the MOTA tab. Point it at the tournament you’re about to register. Plug your real bankroll and the markup someone is actually offering you. The same grid drops out — but your cell is highlighted, the band around it is drawn, and the sell % on that cell is the answer.
Plug your real bankroll, your real markup, the tournament you're about to register. The same heatmap drops out — the cell you sit in is your sell %.