If following baseball for nearly four decades teaches you anything, it’s that the game is so large and encompasses so much that you can see something happen right in front of you and not immediately grasp its significance. And sometimes you still don’t 35 years later, until someone points it out to you. That’s just what Bruce Markusen has done in “The Team That Changed Baseball: Roberto Clemente and the 1971 Pittsburgh Pirates” (Westholme Publishing, 240 pages, $25).

The 1971 Pirates of Roberto Clemente, Willie Stargell, Bill Mazeroski, Dock Ellis, and Steve Blass are among my all-time favorite teams, and their spectacular World Series win over the Orioles of Earl Weaver, Frank Robinson, Brooks Robinson, Jim Palmer, and Dave McNally is one of the great baseball upsets of the postwar era. (That supposedly dominant Orioles team also flopped against the 1969 Mets, but that’s another story.) Still, though I followed their season closely, I never fully understood their impact.

Mr. Markusen, also author of “Roberto Clemente: The Great One,” argues that the Pirates made other teams, most notably the New York Yankees and Oakland A’s, realize the value of opening the floodgates to Latino ballplayers. In addition to Clemente, a Puerto Rican (and the first Latin American player to make the Hall of Fame), the Pirates’ roster included platoon outfielder and pinch hitter Vic Davalillo, a Venezuelan; utility infielder Rennie Stennett, a Panamanian; backup shortstop Jackie Hernandez, a native Cuban; and left-handed relief ace Ramon Hernandez, a Puerto Rican.

Another Puerto Rican veteran of the ’71 Pirates, Jose Pagan, would later become a Pittsburgh coach but was frustrated in his quest to become the first Latin manager in the big leagues. Catcher Manny Sanguillen, a native Panamanian, was more successful in breaking down barriers: He was one of the first Latin catchers to be regarded as competent enough to earn the confidence of a major league pitching staff. Within a few years of the Pirates’ World Series triumph, most major league clubs had heavily beefed up their scouting in Latin America.

Mr. Markusen also provides updates and elegies for this great team. The most colorful of the 1971 Pirates, Dock Ellis, once bragged about having pitched a no-hitter while on acid; he is now a drug counselor and a public speaker. My favorite epitaph is for the Popeye-clone of a manager, Danny Murtaugh: “He never over-managed, and his teams rarely overachieved.”

The heart of that 1971 Pirate team and the legendary 1960 Pittsburgh World Champions was Clemente, the most stylish ballplayer of his era. It wouldn’t be fair to say that Clemente hasn’t had good biographies devoted to him – Mr. Markusen’s 1998 book is more than worthy – but David Maraniss’s “Clemente: The Passion and Grace of Baseball’s Last Hero” (Simon & Schuster, 385 pages, $26), is the first to approach Clemente’s story with both a fan’s passion and an outsider’s ability to convey that passion.

Mr. Maraniss covers much the same territory as earlier biographies, but he has done here for Clemente what his “When Pride Still Mattered” did for Vince Lombardi; namely, to put a stamp of immortality on his subject without casting him in bronze. Details that might seem trivial in the eyes of a lesser writer are used here to illuminate key character traits. For example, Clemente refused to do a cameo in the Jack Lemon-Walter Matthau film “The Odd Couple” because it required him to hit into a triple play, something his pride wouldn’t allow. (They got Bill Mazeroski to do it.)

Mr. Maraniss also emphasizes the Puerto Rican Hall of Famer’s militancy in support of the fledgling players union back in the late 1960s. Clemente was the first Latin players union team representative and, according to union head Marvin Miller, was among the most active of all player reps, a fact overlooked in previous biographies.

***

Writing of Clemente’s involvement with the union, Mr. Maraniss makes an insightful point:

One could argue that in terms of baseball history, [the Mets’ World Series victory] was the second most important story of the year. The most significant event in baseball in 1969, and perhaps of the entire decade, might have taken place after the season on December 13 and 14, inside a conference room at the Shertaon Hotel in San Juan, Puerto Rico, where the Executive Board of The Major League Baseball Players Association held its annual winter meeting.

At that meeting, the Players Association voted to back Curt Flood and his lawsuit against Major League Baseball. Flood’s purpose was to overturn baseball’s so-called reserve clause, which bound a player to his team for life, even after his contract was up. He was to lose in the Supreme Court three years later by a vote of 5-4, but like the Alamo, it was the defeat that rallied the troops and led to the union’s eventual victories.

That story has been told before, but, surprisingly, the toll exacted by the suit on Flood himself has never been described at length. In fact, Flood, one of the most important players in the game’s history in terms of moral leadership, has remained until now a man without a biography. Alex Belth’s stirring and hugely readable “Stepping Up” (Persea Books, 240 pages, $22.95) plugs a significant gap in the history of baseball’s turbulent 1960s and early ’70s.

Flood, the man who told Commissioner Bowie Kuhn, “After 12 years in the major leagues, I do not feel that I am a piece of property to be bought and sold,” was the true torchbearer of Jackie Robinson’s legacy, and Mr. Belth gives him his due. “His life,” Mr. Belth writes, “took a course that never in his wildest dreams he could have imagined as a scrawny kid making trick catches on the ballfields of Oakland. He took a simple stand against baseball,based on simple principles of truth and justice – principles he held on to when it would have been so much easier to let them go.”

It was Flood, Mr. Belth writes, who “made the world stand up and take notice of baseball’s exploitative structure.” But like Robinson before him, he paid the price in terms of stress. He fell into deep depressions during and after the lawsuit, and his heavy drinking and smoking left his body weakened and susceptible to throat cancer. He died in 1997 at age 60.

In “Juiced,” Jose Canseco talks about his willingness to lead players across the picket line in the 1994 strike – does anyone know how we can send him a copy of this book?

Mr. Barra is the author of “The Last Coach: A Life of Paul ‘Bear’ Bryant.” His baseball and football columns appear on The New York Sun’s sports pages.