We examine incentive compatibility of various school choice mechanisms as measured by the number of manipulating students. We find that Boston with Skips Mechanism, Secure Boston Mechanism, and Chinese Mechanism may have more manipulating students than Boston Mechanism. Similarly, Taiwan Mechanism with smaller deductions may induce more manipulating students than Taiwan Mechanism with larger deductions. Computational simulations show that on average Secure Boston Mechanism and especially Chinese Mechanism have fewer manipulating students than Boston Mechanism, while Boston with Skips Mechanism performs slightly worse than Boston Mechanism.