Zlatan Ibrahimovic struck against his old club to earn a point for Milan.
"The team played well, we had chances to win and didn't take them, so it remains positive to emerge unbeaten from Amsterdam," said Allegri.
Allegri has used a different trident attack in every game so far, but switched again with Clarence Seedorf as the top end of a diamond midfield behind Zlatan Ibrahimovic and Robinho.
"We can use this system again or the three strikers, it depends on the characteristics of the players we put on the field.
"I think we could've made more of cross-field passes and players pushing up from behind. Our best chances came from simple moves that allowed us to go clear on goal. We need to improve the movements, but it's difficult when you play every three days and barely have time to train. I am glad to see the side improving physically and psychologically.
"When people say Milan don't run, it's not true. We use up a lot of energy, but not all of it is organised or efficient, so if we learn to do that then we'll be sharper when we have the ball. We trained until August 28, then with international duty and a game every three days it becomes very difficult to work on tactical training.
"When you are working with a team, it's crucial to keep repeating the same movements over and over so they become natural. Of course, also having some individuals who can dream something up is very useful too.
"I have very clear ideas and always have done. You need balance in a side and certain characteristics to co-exist. I try to give my team a certain balance, but to do that I need everyone to work hard and tonight once again they proved that these stars are ready to sacrifice themselves for the team."