Kansas City Royals

For all of his successes as a pitcher, Leibrandt is best known for a series of post-season failures and suffering hard luck. In 1984, Leibrandt and the Royals faced elimination in the best-of-five American League Championship Series against the Detroit Tigers. Leibrandt threw a complete game three-hitter only to lose, 1–0, on a fielder's choice in the second inning.

In the following year's ALCS, the Toronto Blue Jays beat Leibrandt badly in Game 1 but he turned in an effective pitching performance in Game 4. However, he lost when, leading 1–0 in the ninth, he walked Dámaso García, who scored on Lloyd Moseby's double. Responsible for Moseby, Leibrandt watched as the Blue Jays scored twice off reliever Dan Quisenberry and got tagged with the loss. He redeemed himself, however, coming out of the bullpen to replace the injured Bret Saberhagen in Game 7 and picking up the win that sent the Royals to the World Series.

In the World Series against the St. Louis Cardinals, Leibrandt again pitched masterfully for eight innings and entered the ninth inning of Game 2 leading a two-hitter, 2–0. It all fell apart again for Leibrandt, though, as Willie McGee doubled to right. With two outs and McGee on second, three Cardinal hits, the last by future Braves teammate Terry Pendleton, scored four runs and saddled Leibrandt with another loss. Five nights later in Game 6, Leibrandt left in the eighth inning trailing 1–0 despite only allowing four hits. However, this time it was the Royals who rallied and won the game 2–1 on a one-out bases-loaded bloop single by pinch-hitter Dane Iorg. In Game 7 the following night, Kansas City blew the Cardinals out, 11–0, to win their first of two World Series titles.

Atlanta Braves

In 1991, Braves manager Bobby Cox designated Leibrandt the starter for Game 1 of the World Series against the Minnesota Twins. Leibrandt got the start by virtue of his long post-season rest and the fact he was the only Braves starter who had ever pitched in the Metrodome. Leibrandt lost as he pitched decently but was outpitched by Jack Morris. Leibrandt is best known for surrendering a walk-off home run to future Baseball Hall of Famer Kirby Puckett in Game 6 of that series. The first pitch of the inning was a change-up, which Puckett took for strike one. The next one was a similar high and outside fastball, which Puckett took for ball one; pitch three was another fastball for ball two. The fourth pitch, and last pitch of the game, was a weak, high change-up that failed to break. Puckett made solid contact and sprinted for first, as was his usual practice. Only after he saw first base coach Wayne Terwilliger throw up his hands in victory did Puckett realize he had hit a home run. Leibrandt was called upon to enter the game in a highly unfamiliar role – as a reliever late in the extra-inning game, and very late at night. Cox endured some criticism for the move because the Braves still had several relievers at their disposal including left-hander Kent Mercker and right-handers Jim Clancy and Mark Wohlers, but the move made sense on another level, because Leibrandt was the only pitcher left on their roster who had previous World Series experience, and although Leibrandt had been subpar in his Game 1 start, the three hitters scheduled to bat for the Twins in the 11th had been a combined 0 for 6 against Leibrandt in that game, including two strikeouts of Puckett.

Leibrandt played in the World Series with the Braves the following year. The Braves lost that series also, this time to the Toronto Blue Jays in six games. In the final game, in circumstances eerily similar to Game 6 of the prior year's Series, Leibrandt was called in as a reliever in an extra-inning game. Just as in 1991, Cox was criticized for using Leibrandt as a reliever with closer Jeff Reardon and relievers Marvin Freeman and David Nied still available. Toronto rallied for two runs in the top of the 11th on a hit by Dave Winfield. The Braves did manage to get one of those runs back in the bottom of the 11th; however, it was not enough and Leibrandt ended up as the losing pitcher.