What is VOPO in tennis betting?

VOPO (Value Over Pinnacle Odds) is the difference between Tennis Glicko's internal win probability (average of Glicko-2 and Elo models) and the implied probability from Pinnacle's odds. A positive VOPO means the market is undervaluing a player.

What is Green EV in tennis betting?

Green EV is Tennis Glicko's high-conviction value signal. It triggers when VOPO exceeds 12% AND the internal win probability is above 50% — indicating the market is significantly mispricing a player.

How accurate is Tennis Glicko?

Tennis Glicko has 72.8% predictive accuracy over the last 30 days, with a Brier Score of 0.1775 — a standard probabilistic calibration metric used in forecasting.

Why use Glicko-2 instead of ATP rankings for tennis predictions?

ATP rankings are a lagging indicator — they ignore surface specialization, injury returns, scheduling fatigue, and form swings. Glicko-2 updates after every match, adjusts for opponent quality, and models rating uncertainty, making it significantly more accurate for predicting match outcomes.

How to Use VOPO in Practice — Tennis Glicko

Understanding VOPO as a concept is one thing. Using it correctly — at the right time, on the right matches, with the right stake sizing — is what separates a profitable systematic bettor from someone running a lucky streak.

This guide walks through exactly how a PRO subscriber should interact with Tennis Glicko signals from the moment a match is listed to the moment they place a bet.

The 6-Step VOPO Workflow

Open the Matches page

Navigate to /matches. All upcoming ATP and WTA matches are listed with their current VOPO scores calculated against Pinnacle's opening line.

Filter for +EV only

Use the '// +EV ONLY' filter to show matches where our model finds positive expected value. PRO subscribers see all VOPO values; free users see aggregated signal counts.

Read the VOPO column

VOPO% shows the gap between our internal win probability and Pinnacle's implied probability. Green EV (highlighted in #AFF035) means VOPO > 12% AND internal probability > 50%.

Check the surface and form

Click any match to see the surface-specific Glicko-2 ratings, Rating Deviation (RD) for each player, and recent form. High RD = model is less certain → weight this into your decision.

Enable push notifications (PRO)

In Profile → Settings → EV Alerts, enable Browser Push Alerts. You'll receive a push notification the moment a new match qualifies as Green EV — often 24–48 hours before the line tightens.

Act at the opening line

VOPO is most actionable at market opening. Sharp bettors correct mispriced lines within 6–12 hours. If Pinnacle's line moves toward our model's probability, that's CLV (Closing Line Value) — the gold standard of model validation.

How to Read VOPO Numbers

VOPO is displayed as a percentage. Here's how to interpret each range:

VOPO Range

Signal Meaning

< 0%

Negative EV — our model thinks the market is overvaluing this player. No bet.

0% – 5%

Marginal positive edge. Not statistically significant over small samples. Skip.

5% – 12%

Positive EV. Worth tracking. Wait for additional confidence (surface, RD, form).

> 12% + prob > 50%

Green EV — highest-conviction signal. Both edge size and win probability confirm value.

PRO Trader Rules

✓Bet on Green EV signals with VOPO > 12% AND internal probability > 50%

✓Bet at opening line — before sharp money corrects the price

✓Use flat staking (1–2% of bankroll) until you have 500+ bets of data

✓Track CLV — if the line moves your way after betting, the model is working

✗Chase losses by increasing stake size after a losing run

✗Bet on every match — wait for Green EV qualification

✗Ignore surface — a clay VOPO signal on grass carries less confidence

✗Judge the model on fewer than 200 bets — variance is very high in tennis

Using the Simulator for Custom Scenarios

The Match Simulator lets you manually input two players, a surface, and market odds to calculate VOPO on demand. This is especially useful for:

—Matches not yet in our automated pipeline (qualifiers, early-round ITF)
—Verifying VOPO against a different sportsbook's odds
—Testing 'what if' scenarios — e.g., what if the line moves to 1.90?

The 6-Step VOPO Workflow

How to Read VOPO Numbers

PRO Trader Rules

Using the Simulator for Custom Scenarios

See today's Green EV signals