 O'Flaherty was the first reliever in MLB history to record an earned run average below 1.00 with at least 70 appearances in a season, and was the first pitcher in Mariners franchise history to begin his MLB career with seven consecutive wins.O'Flaherty graduated from Walla Walla High School in Walla Walla, Washington.As a senior at Walla Walla High School, he had a 5–2 win–loss record, an earned run average (ERA) of 1.99, and 83 strikeouts.