Ideal for teaching large groups. This screen shot of a partly played hand showing the principles of a simple squeeze can be projected on to your projector screen (needs a computer projector) or through your TV.
Here, South lost one trick to rectify the count in 6 spades, now the play of the last trump forces west to make a fatal discard. Students find this much easier to follow when they can see the cards played dynamically on a screen like this, and most modern laptops can display through a TV screen to a large audience:
If you prefer hands can be shown in normal card format:
Or you can switch on Double Dummy analysis and it shows you the winning (green) and losing (red) plays at each stage (plus number of overtricks and undertricks if you want it). In the hand below if East is on play as a defender then a diamond or 10H will let the contract make and anything else defeats it: