Robot Games Daily EV Drill
Pay to play a wager, or pass. 10 rounds, 6 to 12 seconds each, scored against the expected value. The free session changes every day and runs in your browser with no signup.
10 rounds · Play or Pass · today's session
Each round offers a wager: pay to play for a chance at a payout, or pass. You have 6 to 12 seconds to decide. A decision is correct if it matches the sign of the expected value, whether or not the round pays out. Everyone gets the same 10 rounds today.
How a round works
Each round offers a wager: pay a fixed cost for a chance at a payout, or pass for $0. For example, pay $3 for a coin flip that pays $10 on heads and $0 on tails. The expected value is 0.5 × $10 + 0.5 × $0 − $3 = +$2, so Play is optimal, even though this flip still has a 50% chance of losing your $3. Market-making decisions are judged the same way, because one trade's outcome does not tell you whether the decision behind it was sound.
Why rounds are scored on the decision
The prep guide's section on trading games explains how market-making interviews are graded: whether your spread reflects your uncertainty, whether you update fair value correctly as information arrives, and how you handle being picked off by a better-informed counterparty. Whether you "won" the round is not part of the grade. Robot Games reduces that judgment to one question per round: given what you knew when you decided, did you pick the right side of zero? A run of unlucky positive-EV rounds is normal and is no reason to stop following the math.
Related practice
- Probability & EV Practice: the typed-answer version of the same skill
- Quant interview brain teasers: worked EV and probability puzzles
- How to prepare for a quant trading interview: trading games, negative marking and a full study plan
Questions
What is Robot Games?
A timed Play/Pass expected-value drill. Each round offers a wager (pay $X for a chance at a payout), and you have 6 to 12 seconds to play or pass. 10 rounds per session.
How am I scored?
By whether your decision matched the sign of the round's expected value. Play is optimal when EV is positive. Pass is optimal when it is zero or negative. A positive-EV play that loses this round is still the right call, and a negative-EV play that happens to win is still the wrong one.
What's a good score on this drill?
7 of 10 optimal decisions is a reasonable target. This is a daily practice drill with no firm cutoff. Net pnl is shown next to your score, but the target is based on decisions, because a positive-EV round can still lose money.
Is this the same as a market-making interview?
No. A trading-game interview is live, multiplayer and adaptive, with an interviewer or counterparty reacting to your quotes. This is a solo, timed drill for the same judgment (does the decision match the sign of the expected value?) without a live counterparty. Practice the live version with another person as well.
Why is the session the same for everyone?
For the same reason every test on this site is a fixed set: scores are comparable, and the free web tier stays a step below the TradeMind app's free tier, which generates new sessions on demand. The app also has unlimited play, firm-specific question packs and Make a Market mode.