Card tables, casino classics, puzzles and a couple of useful tools, made by Michael Orlov in Israel. The casino games play for chips only: no real money, ever.
On an invented 30-stop strip with a symbol on 6 stops, spreading it out shows it in 18 of 30 windows, always on one row. Stacking it shows it in 8 of 30, and 4 of those fill all three rows. The average rows filled is 0.6 either way.
A 1 degree error in the cue's line moves the cue ball 17.5 mm off course over a metre; 2 degrees moves it 34.9 mm. Bridge length, stance and a straight stroke exist to keep that angle small.
A worked Malmuth-Harville calculation for a three-player 50/30/20 finish. Stacks of 5,000, 3,000 and 2,000 give prize equities of 38.39%, 32.75% and 28.86%, and a fair coin-flip all-in costs both players who take it.
Pot odds tell one hand what equity it needs. Minimum defence frequency, pot ÷ (pot + bet), tells a whole range how much to continue: 66.7% against a half-pot bet, 50.0% against a pot-sized one, and where the formula misleads.
Four players with 7 tiles each use all 28 tiles, so there is no boneyard. Holding 4 of a number leaves 3, and your partner has none of them 27.4% of the time. Tactics for helping a partner.
A diesel-electric train runs a generator and traction motors; an electric train draws power from overhead wire (1.5 kV or 3 kV DC, 15 kV 16.7 Hz or 25 kV 50 Hz AC) or a 750 V DC third rail. Higher voltage means less current for the same power.