Same game as last time. New question: what is your disagreement with the market actually worth — in cents, per hundred dollars, over the long run?
From Activity 01 you know the market has Detroit at 55.6% and Boston at 48.8%. Take the 4.3% margin out and the market's genuine opinion is Detroit 53.3%, Boston 46.7% — fair prices of 1.88 and 2.14. You're offered 1.80 and 2.05. Both worse than fair. That's the fee.
EV percentage, one decimal place. Two of these have you more confident than the market — only one is a bet.
| Your read | Price | EV % |
|---|---|---|
| Detroit 60% | 1.80 | |
| Detroit 55% | 1.80 | |
| Boston 50% | 2.05 | |
| Boston 45% | 2.05 |
At 55% you're above the market's true read of 53.3%. You genuinely rate Detroit more than the market does. And you're still losing a dollar every hundred.
Being right about the direction was never enough. Your edge has to clear the margin before it's worth anything. That's the amber strip on the slider — the zone where you disagree with the market and it still costs you money.
Same answer the formula gave. The formula is just the shortcut.
In percentages: you think 60%, the market thinks 53.3%, you have a 6.7-point edge.
In price: 60% is worth 1.67, you're offered 1.80. You're being paid 1.80 for something worth 1.67.
Get comfortable flipping between the two. The second is faster once it clicks, and it's how you spot a bad price on your phone in twenty seconds.
EV is only ever as good as your probability. The formula never fails. Your 60% does. Everything a tipping service is actually selling — everything I'm selling — is the quality of that number. The maths after it is arithmetic a twelve-year-old can do.
Which is why the results are published to the unit, and why ROI is the figure that matters. ROI is realised EV. If the probabilities are real, the two converge over enough bets. If they're not, no formula saves it.