"'Right,' Wood said, his eyes glinting. 'Now, Quidditch is easy enough to understand, even if it's not too easy to play. There are seven players on each side. Three of them are called Chasers.'
'Three Chasers,' Harry repeated, as Wood took out a bright red ball about the size of a soccer ball.
'This ball's calles the Quaffle,' Wood said. 'The Chasers throw the Quaffle to each other and try to get it through one of the hoops to score a goal. Ten points every time the Quaffle goes through through one of the hoops. Follow me?'
'The Chasers throw the Quaffle and put it through the hoops to score,' Harry recited. 'So- that's sort of like basketball on broomsticks, isn't it?'
'What's basketball?' said Wood curiously.
'Never mind,' said Harry quickly.
'Now, there's another player on each side who's called the Keeper-I'm the Keeper for Gryffindor. I have to fly around our hoops and stop the other team from scoring.'
'Three Chasers, one Keeper,' said Harry, who was detremined to remember it all. 'And they play with the Quaffle. Okay, got that. So what are they for?' He pointed at the three balls left inside the box.
'I'll show you know,' said Wood. 'Take this.'
He handed Harry a small club, a bit like a short baseball bat.
'I'm going to show you what Bludgers do,' Wood said. 'These two are the Bludgers.'
He showed Harry two identical balls, jet black and slightly smaller than the red Quaffle.Harry noticed that they seemed to be straining to escape the straps holding them inside the box.
'Stand back,' Wood warned Harry. He bent down and freed one of the Bludgers.
At once, the black ball rose high in the air and then pelted straight at Harry's face. Harry swung at it with the bat to stop it from breaking his nose, and sent it zigzagging away into the air - it zoomed around their heads and then shot at Wood, who dived on top of it and managed to pin it to the ground.
'See?' Wood panted, forcing the struggling Bludger back into the crate and strapped it down safely. 'The Bludgers rocket around, trying to knock the players off their brooms. That's why you have two Beaters on the team - the Weasley twins are ours - it's their job to protect thier side from the Bludgers and try and knock them towards the other team. So - think you've got all that?'
'Three Chasers try and score with the Quaffle; the Keeper guards the goals; the Beaters keep the Bludgers away from their team," Harry reeeled off.