The 1991 Caribbean Series (Serie del Caribe) was the twenty-first edition of the second stage of the Caribbean Series. The series was not actually called the Caribbean Series, instead it was known as Winterball I. It was the only such event, as the organizers realized it was a flop and led to a huge financial loss for the sponsor, ProServ. All games were held at Bobby Maduro Miami Stadium in Miami, FL, United States from February 5 to February 11. The series featured four teams from Dominican Republic, Mexico, Puerto Rico and Venezuela. The Tigres del Licey of the Dominican League won the series and were managed by John Roseboro. The Most Valuable Player of the round-robin was Gerónimo Berroa, an outfielder with the Tigres del Licey, while another Licey OF, Jerry Brooks, was MVP of the finals.

Unlike previous series (or future ones), Winterball featured a three-game round robin, followed by a playoff round. The most dominant team in the series was the Tigres del Licey, who went 3-0 in round-robin competition and then won 13-4 and 13-1 over the Cardenales de Lara in finals of the playoffs. Licey outscored their opposition 50-8. The finals MVP was OF Jerry Brooks, who hit .473 with 10 RBI while outfield mate Geronimo Berroa (.479) was MVP of the round-robin segment. Other key players for the Tigres included 1B Henry Rodriguez, P Juan Guzman and P Jeff Hartsock.

The three non-Licey clubs each were 1-2 in the round-robin part of the tournament, leading to a playoff in which Lara beat both Tijuana and Santurce once each.

Final Standings[edit]

Batting Average: .471 - Gerónimo Berroa , Tigres del Licey
Home Runs: 1 - Nine tied
Runs Batted In: 10 - Jerry Brooks , Tigres del Licey
Wins: 2 - Melido Pérez , Tigres del Licey

Team	League	G	W	L	WPCT	Manager
Tigres del Licey	DOM Dominican League	5	5	0	1.000	John Roseboro
Cardenales de Lara	VEN Venezuelan League	7	3	4	0.429	Alfonso Carrasquel
Cangrejeros de Santurce	PRI Puerto Rican League	4	1	3	0.250	Mako Oliveras
Potros de Tijuana	MEX Mexican Pacific League	4	1	3	0.250	Joel Serna