The replay says why: a travel, a drive that was cut off, and the defender who chose to help

basketball.casa is a basketball league where every game is simulated. Nobody scripts the plays. Each one comes out of who the players are at that moment: how tall, fast and tired they are, what they can see, and what they decide. You can watch any game back exactly as it happened. This update is about the moments you can see but could not read: three plays where the game already knew why something happened, and now the replay tells you.

Why a travel was called

Travels are rare, about one in every five hundred possessions, and they used to arrive with no reason given. A travel here is not a coin toss. It comes from how fast the player was moving when they gathered the ball, and how long they held it afterwards: run in quickly, or wait too long after the catch, and the steps run out. Now the caption says how many steps the rules allow and how likely a travel was, and the player's card gives the two numbers it came from. In one game a player gathered at 3.6 metres a second, held the ball for nine tenths of a second, and had about a one in three chance of being called. They were.

How far a stopped drive got

When a defender slides across and cuts off a drive, the driver still gets somewhere first. From a distance it can look as if they simply stopped. Now the caption names the defender and says how far the driver got around them, and the card adds the time the defender needed to react, stop and cut across. A quick first step against a slow slide gets deeper, and you can read by how much: "got 0.94 m round them in the 0.61 s they needed to cut across".

The defender who chose to help

When a drive beats its defender, the next defender has a choice: step across and help, leaving their own player, or stay home. Real defences live and die on that decision, and here it happens about twice a minute. Every option has a price, worked out from where everyone is standing: the points the defence can expect to give up either way. The card now says what the helper chose and what both choices were expected to cost. The cheaper option is not always the one taken: each player weighs the two with their own decisiveness, so some pick the better one nearly every time and others are less sure. The card says how likely the choice they made was.

One we measured and did not build

With all these plays explained, a card is on screen for about half of a game. We tried showing the drive's card for less time. It took no cards away, only reading time, and the card never covered the ball, the hoop or a score. So it stays as it is, and the next question is which plays deserve a card at all.