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Sizing & Bankroll

What it is

Sizing is half the game. Two bettors with the same picks can have opposite outcomes if one sizes 5u on a C-tier hunch and the other sizes 0.5u. Our recommended sizing is tier-driven, capped, and Kelly-adjacent without being Kelly-aggressive.

When to use it

How to read it

Unit conventions

1 unit = 1% of bankroll. A $10,000 bankroll has 1u = $100. Recompute monthly. Do not adjust units mid-month after a loss.

Tier-based sizing

TierWhat it meansSuggested size
AMulti-book sharp confirmation, model agreement, calibrated soft book offering, clean enrichment.1.5 to 2.0 units
BSolid edge but missing one element (e.g. only two sharp anchors, or model neutral).1.0 unit
CSpeculative: thin anchors, larger EV but more noise. Smaller positions, often parlay candidates or fades.0.5 unit

Hard caps

Kelly criterion (for the curious)

Kelly fraction f = (bp - q) / b where b is decimal odds minus 1, p is fair prob, q is 1 - p. Full Kelly maximizes long-run growth but has enormous variance. Most pros use quarter Kelly (0.25 × f) or half Kelly (0.5 × f). Our tier-based sizing approximates quarter-to-half Kelly for typical edge sizes (3-6%).

Worked example

Example sizing day
Bankroll: $20,000 (1u = $200)
Day's plays:
  1. NFL spread, tier A, EV 4.1%       -> 2.0u = $400
  2. NBA player prop, tier B, EV 5.8%   -> 1.0u = $200
  3. MLB longshot ML +475, tier C, EV 6.2% -> 0.5u = $100 (longshot cap honored)
  4. NCAAB total, tier A, EV 3.2%       -> 1.5u = $300

Total staked: 5.0u = $1,000. AT the daily cap.

New pick arrives at 7 PM: NHL ML, tier B, EV 4.0%.
Decision: skip. Cap reached. Tomorrow.

Even when the new pick looks good, the cap holds. The cap is not the enemy of opportunity, it is the enemy of overconfidence.

Common mistakes

  1. Sizing by feel. Feel is variance disguised as conviction. Use the table.
  2. Doubling up to recover losses. Martingale is the fastest way to ruin. The right size today is the same as the right size yesterday.
  3. Treating bonus money as house money. Once it's in your account, it is your money. Size identically.
  4. Ignoring correlation. Two NBA totals tonight could be two outcomes of the same league pace anomaly. One bet, not two.
  5. Pushing past the daily cap. If the cap feels restrictive, the cap is working. It exists for the days variance is brutal.

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