Yield (often called ROI in betting) divides net profit by total amount staked: 100 bets of 1 unit returning 6 units of profit is a 6% yield. Because it normalises by turnover, yield lets you compare records of different sizes and odds profiles fairly — unlike raw profit, which rewards simply betting more.
Context for calibration: long-term yields of 3–8% are strong professional territory; double-digit yields over large samples are rare and usually shrink as sample size grows. A spectacular yield over 30 bets is variance, not skill — always read yield together with the number of settled bets, and be suspicious of any record that never shows a losing stretch.
120 settled tips at flat 1-unit stakes, net +7.9 units: yield = 7.9 / 120 = 6.6%. The same +7.9 units over 400 bets would be a 2.0% yield — a materially weaker (though still positive) record.