According to you, does it mean that if there is no crit in the first 9 attacks, then the crit rate of the tenth attack is 100%?

In that case, let's use it up.

There is only one attack, and the probability is 0. 1.

Attack twice, probability =0.9*0.2.

Attack three times, probability =0.9*0.8*0.3.

Attack four times, probability =0.9*0.8*0.7*04.

.. and so on, attack ten times, the probability = 0.9 * 0.8 * 0.7 * 0.6 * 0.5 * 0.4 * 0.3 * 0.2 *1.

Then define E=∑P*N according to expectations, where n is the number of attacks and p is the corresponding probability, and it can be calculated.