Low pair or 4 to a straight in Double Double Bonus?
Keep the straight draw. 9-10-J-Q is worth 0.8085 per coin on 9/6 Double Double Bonus vs 0.7332 for the pair of nines — the reverse of Jacks or Better.
The exact numbers — 9♥ 9♠ 10♠ J♣ Q♦
EVs are exact — every possible draw enumerated, not simulated — at max bet on 9/6 Double Double Bonus. Check it yourself: the analyzer runs the same solver in your browser.
See all 32 holds of this hand ranked →Why
Nearly all of a low pair's value is two pair and trips, and Double Double Bonus pays those 1 and 3 instead of 2 and 3 — so the pair loses value while the 4-coin straight keeps all of its own. Either nine plays: holding 9♥ or 9♠ with 10-J-Q solves to the identical 0.8085. On 9/6 Jacks or Better the same five cards go the other way, 0.8237 for the pair against 0.8085 for the draw. A player who brings the Jacks or Better rule to a Double Double Bonus machine gets this backwards every time.
Chart line #20 of 39 — '4 to an outside straight with a high card' sits above line #21, 'Low pair'. On the 18-line Jacks or Better chart that order is inverted. See the full solver-optimized strategy chart, or drill hands with exact-EV feedback until plays like this are automatic.