<human>: Can you give me a shortened version of the text?

This happened about when I was about 14 so around 4 years ago now, I was in secondary school (high school for the Americans) and there was a group of around 11/12 that all played manhunt (tag but on a much bigger scale) during our lunch break. This particular day, I was chosen to be on at the beginning and everyone else had run off by the time I'd finished counting. I spotted a group of them on the other side of the school tennis courts so I went after them. Our school had these large metal fences around the edge of the courts that had these big heavy metal gates so you could get in and out of the courts. The gates have these pegs that go into holes in the ground so they'd stay shut, that bit is important. So I was chasing after them and they eventually went back into the courts toward one of the gates. Now, this gate was the one that everyone used but no one ever lifted up the peg from the ground when using in. This had lead to a section of the Tarmac (asphalt) being worn away. After the bit that had been worn away it went back to its normal height which meant that went the gate was pushed with the peg down it would get stuck on this ledge. Well when the group I was chasing ran through the gate it was open and so to slow me down they threw it shut with the peg. At this point I didn't see the peg was down so, whilst sprinting I ran into the gate and pushed. It of course got stuck, and I, still sprinting at this point, ran head first into it and cracked my head open. It would've been pretty funny to listen to most people's reaction when I stood up with a face covered in blood, except it hurt so much haha. The teacher who came over pretty much just went 'oh shit' and then almost fainted.
<bot>: I ran head first into a metal gate and cracked my head open causing half of my face to be covered in blood and my teacher to almost faint.