------
## 最终结论
```python
def find_rotation_count(arr):
    left, right = 0, len(arr) - 1

    while left < right:
        mid = (left + right) // 2
        
        # Check if mid is greater than the next element
        if mid < right and arr[mid] > arr[mid + 1]:
            return mid + 1
        
        # Check if mid is less than the previous element
        if mid > left and arr[mid] < arr[mid - 1]:
            return mid
        
        # Decide which side to go
        if arr[mid] >= arr[left]:
            left = mid + 1
        else:
            right = mid - 1

    return 0
```