I'm talking about attacking a rival team's gym.
Sometimes my whole army of Pokemon are allowed in the battle (that's awesome because they can take turn to fight until it times out of course). However, many times only 1 of my Pokemon is allowed which makes it almost impossible to take down gym.
Even stranger, the 1 Pokemon I was allowed to use in gym fight was not even the strongest one. So, how was it selected.
I've been trying to observe and figure out the pattern myself without success