The in-season tournament is not the first time that an extra event was organized alongside the Cup Series season, with various formats done through NASCAR history. The first was the
Winston Million from 1985 to 1997, giving a driver a cash prize for their victory in four assigned races. In 1998, the format was expanded to five races and became the
No Bull 5, a challenge where a driver must finish in the top 5 and then win in two consecutive Crown Jewel races to earn a million dollar prize. This format lasted until 2002. With the advent of the
Chase for the Cup in 2004, later reformulated as the
NASCAR playoffs in 2014–2017, the idea of a mid-season event was instead used in the lower tiers of NASCAR competition. In 2009, NASCAR adopted the
Dash 4 Cash for its Nationwide Series, now named the
O'Reilly Auto Parts Series. In 2019, the
Triple Truck Challenge was adopted in the
Truck Series. Both are organized to this day alongside the regular seasons and chase for both series. The idea of a in-season format based on
March Madness and the
NBA Cup (which was introduced in 2023) was conceptualized by Cup Series driver and
23XI Racing co-owner
Denny Hamlin, first publicly mentioned in his podcast
Actions Detrimental. According to Hamlin, the Cup season needed more storylines during the mid-summer part of regular season as he felt there wasn't much buzz and too few stories going on in the series until the final races before the Playoffs. Hamlin himself realized a non-official version of the format during the 2023 and 2024 seasons. The format, along with his podcast, became successful enough to get the attention of NASCAR leadership, who decided to turn the concept idea into an official mid-season event from the 2025 season. Upon the announcement, Denny jokingly mentioned that he wanted to win the million-dollar prize for the first In-Season Challenge as
royalties. ==Format==