Remember to read the intro.
This circuit breaker will count the number of failures in a certain time window. If the threshold is exceeded it will transition into the FAILING state and stay there for a period of time. Once RECOVERING it will count failures in another time period and if all are successes then the breaker is considered OK again.
The biggest flaw with this breaker is that as number of requests per second increase the threshold for failures may be too low causing the circuit breaker to start FAILING even at a low percentage of failures.