ISM Connect 300

The ISM Connect 300 was a Monster Energy NASCAR Cup Series stock car race that was 317.4 miles (510.8 km), traditionally held in mid-September at the New Hampshire Motor Speedway in Loudon, New Hampshire, the other one being the Ambetter 301 in July.

The New England 300 also has the distinction of being the only NASCAR Cup Series points race outside Daytona and Talladega to run a restrictor plate race since the adoption of the current 358 cubic inch formula. After Adam Petty's fatal crash in the Busch Series practice on May 12, 2000, and Kenny Irwin Jr.'s fatal crash in the Cup Series practice on July 7, 2000, NASCAR decided to run restrictor plates, already used for the Whelen Modified Tour races at the circuit, for the 2000 Cup race, then known as the Dura Lube 300 sponsored by Kmart. Adding restrictor plates did have the desired result of slowing down the cars drastically, but at the same time, restricted passing so much that Jeff Burton led all 300 laps. This lack of passing was so noncompetitive that, for Cup cars only, the restrictor plates were gone for the very next race, the 2001 New England 300.

From 2004 until 2010, the race served as the opening round of the Monster Energy NASCAR Cup Series playoffs, a ten-race "playoff" designed among the top ten (twelve as of 2007) drivers in the standings of the series following the Chevy Rock and Roll 400 to spur interest in a championship series while NASCAR faces competition from the start of the NFL season and college football, the pennant races and post-season of Major League Baseball and the outset of the NHL and NBA seasons. Beginning with the 2011 Chase, the race became the second race in the ten-race playoff; as in part of a new round of schedule realignment the Overton's 400 at Chicagoland Speedway moved from its traditional early July race date. On March 8, 2017 it was announced that the fall NHMS date would move to Las Vegas Motor Speedway starting in 2018.