In 1989, the first full season with night baseball at Wrigley Field, Don Zimmer's Cubs were led by a core group of veterans in Ryne Sandberg, Rick Sutcliffe and Andre Dawson, who were boosted by a crop of youngsters such as Mark Grace, Shawon Dunston, Greg Maddux, Rookie of the Year Jerome Walton, and Rookie of the Year Runner-Up Dwight Smith. The Cubs won the NL East once again that season winning 93 games. This time the Cubs met the San Francisco Giants in the NLCS. After splitting the first two games at home, the Cubs headed to the Bay Area, where despite holding a lead at some point in each of the next three games, bullpen meltdowns and managerial blunders ultimately led to three straight losses. The Cubs couldn't overcome the efforts of Will Clark, whose home run off Maddux, just after a managerial visit to the mound, led Maddux to think Clark knew what pitch was coming. Afterward, Maddux would speak into his glove during any mound conversation, beginning what is a norm today. Mark Grace was 11–17 in the series with 8 RBI. Eventually, the Giants lost to the "Bash Brothers" and the Oakland A's in the famous "Earthquake Series."

What year was the first full season with night baseball at Wrigley Field?