1. Sandy Koufax
Every sport has its version of Jim Morrison—the guy who walked away in his prime, leaving only a legacy of youth, beauty, and brilliance. Okay, Morrison may not have been brilliant, nor was he particularly beautiful at the time he gained admittance to Père Lachaise, but you get my meaning and you probably really want me to stop rhapsodizing about Jim Morrison. So I won’t tell you about my own visit to Père Lachaise, and how by the time I went there, I was more interested in visiting Balzac and Collette than I was the final resting place of the Lizard King. I certainly won’t tell you about how hard it is to find Morrison’s grave without a map. By the way, I’m talking about Jim Morrison, lead singer of the Doors, not Jim Morrison, third baseman of the White Sox and Pirates.

What was I saying? Oh yes, like Michael Jordan in the NBA and Jim Brown in the NFL, Sandy Koufax walked away from his sport when he was playing at a level almost no one had before. Unlike Jordan, who kept coming back, and Brown, who kept talking about it, Koufax retired and that was it. A private man, we really haven’t heard from him since. For years after he quit, he’d show up to Dodgers training camp in Vero Beach, Fla., and well into the 1980s stories would circulate about how well he could still sling a baseball. These tales might have been apocryphal, but I will choose to believe them because it seems really cool to think that a 50-something Koufax was still wowing them while Reagan was in the White House.

It’s easy to play what-if with Koufax’s career. What if his arm hadn’t gone bad? How many games would he have won? What if he could have had the benefit of modern sports medicine? If he played for the White Sox, would they have made him a closer? As it was, he made the best-ever case that a relatively brief, but historically elite, career is enough to earn a spot in Cooperstown.

According to the B-Ref version of WAR, Koufax compiled 41.7 WAR over his last five seasons. Only one other pitcher is over 30—Eddie Cicotte at 32.4, and he was forced to quit due to greed and treachery. Tied for third is Lefty Grove and Hippo Vaughn at 25.3, then comes the sad case of Addie Joss. On the hitter’s side, Roberto Clemente leads the way with 32.8. When you look at just final seasons, you can start to get a feel for just how shocking it must have been when Koufax retired. He stepped away after a 10.6 WAR season… the second-best is Shoeless Joe Jackson’s 7.3. That, my friends, is leaving them wanting more. Oliver Stone should make a movie. —Bradford Doolittle

2. Kirby Puckett
I'd just turned 17 in March 1996 when Kirby Puckett, who had missed the final three-and-a-half games of 1995 after being hit square in the face by a Dennis Martinez fastball, reported some blurry vision. He'd been a fixture on my favorite team since I was 5, and my favorite player in baseball for at least half that long. The first few months of that summer were miserable, watching the Twins go through the motions—not terrible, which is how I remember them, but mediocre and certainly terribly dull without Kirby—and reading the daily updates-sans-actual-update on his condition, until finally, in mid-July, he announced his retirement. We all kind of suspected it was coming by then, but it still stung a lot when it finally came.

Kirby was already 36 (then listed at 35, which was corrected long afterward), and spending most of his days in right field or at DH rather than his familiar center. He probably didn't have any more top-five MVP finishes left in him, and certainly didn't leave another World Series title on the table (not with those Twins, anyway). But he was still a fine hitter, putting up a .295 TAv in 1995 that topped his career average, and had looked as great as ever in spring training '96.

The injury didn't steal any truly great seasons from us, but it did arguably do two things: First, without the injury, Puckett likely gets very near 3000 hits, and adds the 6-8 WARP he needs to erase any doubt, in the minds of most traditionalists and statheads alike, over whether he's truly a deserving Hall of Famer. Second, without the injury, there's a very good chance that his whole life heads in a different direction: It's all half-formed conjecture, but if his career ends gracefully and on his terms, maybe he stays around the game, stays out of trouble, and manages to retain his spotless public image. Maybe he's better able to take care of himself physically and is still alive today, still just 52 years old, and for many years to come. It may not have meant a ton in the standings or record books, but the glaucoma that ended Kirby Puckett's career may well have robbed us of one of the game's great heroes. —Bill Parker

3. Herb Score
Baseball history is littered with pitchers whose arms both gave them their promise and prevented them from reaching their full potential. Some never made it to the majors before breaking down, leaving us with nothing to dream on but eyewitness accounts and stats against inferior competition. Others made it to the majors for a tantalizingly short time, only to fall apart physically and either retire or return in a greatly diminished state.

Herb Score may have been the best of the tantalizing type. Score’s fastball was ranked the seventh-best ever by a 1957 BBWAA poll, and he complemented it with an above-average curveball. In tandem, the two pitches were devastating. Here’s a surprising stat: In 1955, Score’s Rookie of the Year season, the average strikeout rate among major-league pitchers was 4.4 batters per nine innings. In 2011, it was 7.1. Score’s 1955 strikeout rate would have led all pitchers with at least 180 innings pitched in 2011. Score was like an ace from the future sent back to a more contact-prone time.

Score’s 9.7 K/9 in ’55 was not only easily the highest in history at the time—before Score, Hal Newhouser’s 8.5 in 1946 was tops among starters—but it also outpaced that of his closest contemporary, fellow phenom Bob Turley, by a full two strikeouts per nine. Aside from Score, only five starters since 1900 have led a season’s second-place starter in strikeout rate by at least two Ks per nine: Dazzy Vance, Sandy Koufax, Nolan Ryan, and Randy Johnson. All four are either in the Hall of Fame or (in Johnson’s case) about to be.

Score’s dominance continued in his sophomore season, when he held lefties to a .126/.251/.192 line in 186 plate appearances. According to WARP, only one major-league pitcher—teammate Early Wynn—contributed more to his team from 1955-1956 than Score, who racked up 12.9 wins above replacement in his age-22-23 campaigns. Dwight Gooden is the only pitcher ever to have a more valuable first two seasons. Of course, staying power is what makes some starters special, and that’s the skill Score (and Gooden) lacked: He’d earn only 1.1 WARP more before calling it a career.

An injury ended Score’s career, but there’s some debate about which one. On May 7, 1957, Score was struck in the right eye by a liner off the bat of Gil McDougald. It was ugly: First he looked like this, and then he looked like this. As painful as the injury was, though, he recovered from it, and it’s probably more accurate to pin his demise on overwork, bad mechanics, and an elbow that started hurting in 1958 and never stopped than on McDougald’s batted ball.

Herb Score was the best pitcher in baseball as a 22-year-old rookie. If his arm had held up, he might have had a chance to be even better. Perhaps, like fellow southpaws Koufax and Johnson, he would have conquered his early control problems and gone on to be even greater. Unfortunately, we’ll never know, which is disappointing even to someone born three decades after his heyday.

For more on Score, see Steven Goldman’s eulogy from 2008Ben Lindbergh

4. Adam Greenberg
On July 7, 2005, Cubs prospect Adam Greenberg was hit in the helmet by the very first major-league pitch he ever saw, a fastball from Valerio de los Santos. (This ESPN “Outside the Lines” feature has the disturbing video.) Seven years later, he has not made it back to the big leagues, although he was insisting as recently as last year, in an in-depth interview with Baseball Prospectus, that he will return.

The road back has been long and hard. The beaning gave Greenberg a form of vertigo and crippling headaches, and it badly disrupted his eyesight. He wound up bouncing around a few organizations before latching on in 2010 with the Bridgeport Bluefish of the unaffiliated Atlantic League—and in 2011, he faced de los Santos again. (He singled. Here is a good story about that day, and about Greenberg.)

Greenberg does not appear to be playing anywhere so far in 2012. He sells a natural supplement made of velvet deer antlers, which he used to treat a serious shoulder injury in 2009. If Greenberg never reaches the majors again—it seems, sadly, almost certain that he won’t—he and Philadelphia’s Fred Van Dusen (1955) will be known as the only players in history to have their career end after being hit by a pitch in their first big-league at-bat, without ever taking the field. Theirs is the deep disappointment of never getting to find out, even for one full inning, what might have been. —Adam Sobsey

5. Tony Conigliaro
Unless your dad is from Southie, you may not know who Tony Conigliaro was. Conigliaro hit .290/.354/.530 in 111 games for the Red Sox in 1964. That, you'll agree, is a very good line. What made it silly-good though was this: Conigliaro was 19 at the time. For context, when he was 19, Alex Rodriguez played in 48 games and hit .232/.264/.408. That same 1964 season, Conigliaro out-hit a 24-year-old Carl Yastrzemski. Over the first four seasons of his career (including 1964), Conigliaro hit .276/.339/.510 with 104 homers, including the 32 that led the American League in 1965. His OPS was 32 percent above average. He was really good, and because he was also really young, he carried the promise to get better.

Then, in an August, 1967 game against the Angels, Conigliaro was hit in the face by a Jack Hamilton pitch. It shattered his cheekbone and blew his eye up so he looked like this:

That pitch ended his season, though not his career. Conigliaro missed the 1968 season as well but returned at the start of the 1969 season. He was almost as good as he had been and the next year he was better, hitting .266/.324/.498 with 36 homers. But lingering problems from the beaning forced him to retire the next year. He returned briefly in 1975 but then had to retire for the final time after just 21 games.

What could have become of Tony C. had he not taken that pitch to the eye on that fateful day? Some say he would have been a Hall of Fame, but that stretches thin our ability to see the future. All we can know for sure is he would probably have been a well above-average player for the Red Sox for a long time. —Matthew Kory

6. Mickey Cochrane
Mickey Cochrane may be the best catcher of the pre-integration era. Bill James, in his New Historical Abstract, called Cochrane the fourth-greatest catcher of all-time, behind only Yogi Berra, Johnny Bench, and Roy Campanella. Cochrane won two American League MVPs during the heights of the live-ball era, once for the Philadelphia Athletics in 1928 and once for the Detroit Tigers in 1934. He was only the third player to win a second MVP award (after Rogers Hornsby and Jimmie Foxx). On May 25, 1937, Cochrane was beaned by a ball pitched by Yankees hurler Bump Hadley. This was 17 years after the death of Ray Chapman, but still years before any kind of protective headgear was being used. The pitch cracked Cochrane's skull in three spots and put the catcher in a coma for 10 days. Cochrane came back to manage the Tigers some that year (and then again in 1938), but he couldn't finish either season. He never played in a game again.

In the wake of the devastating injury, teams started experimenting with headgear. Within the week, Connie Mack's Philadelphia A's played around with polo helmets (see photo) during batting practice. In Des Moines, the Western League's Demons actually wore polo helmets in a game, but they didn't take. There was no serious movement on a batting helmet until the 1940 season, when Brooklyn's Pee Wee Reese and Joe Medwick were both victims of dangerous beanings. It was then that National League President Ford Frick began encouraging teams to wear a new helmet, which later led to the in-cap protective plate and, eventually, the batting helmet we now know (a full timeline can be found here). There may not be a clear, decisive line linking the two events, but I feel certain that the protective headgear ball would not have started rolling so quickly in 1940 if it weren't for the dangerous and near-fatal injury the star and future Hall of Famer Cochrane experienced only a few years before. —Larry Granillo

7. Brien Taylor
With Gerrit Cole disqualified, as he's only just begun his career, Brien Taylor remains the only pitcher selected with the first overall pick in the draft not to throw off the mound in a big-league game. Still, he's an important piece of big-league history. Many scouts still insist he's the best left-handed high school pitcher they have ever seen: a 6-foot-3 pure power arm who could touch 99 mph.

Selected by the Yankees with the first pick in June of 1991, Taylor held out and turned into one of Scott Boras' early draft success stories, with his $1.55 million bonus more than doubling any other deal in the 1991 draft and nearly tripling the record for a top pick. His minor-league career was spectacular early on, as he reached Double-A in his second full season. Control problems were the only ding against him. He looked like a future ace with a chance to pitch in the big leagues by the end of 1994. All of that changed a week before Christmas 1993 when, in a story that still has many versions, Taylor injured his shoulder in a fight. The damage was massive, and Taylor did not return to the mound until the end of the 1995 season when he had a 6.08 ERA in 11 Gulf Coast League starts. His velocity never returned, his control problems reached Steve Blass proportions, he got fat, he got hurt more, and by the end of the 2000 season, he was out of chances. Baseball really was Taylor's only way out from a lower-class upbringing, and once he was out of baseball, he had multiple run-ins with the law, including his most serious charge in March when he was charged with trafficking cocaine. It's a sad story, ultimately, as more than 21 years later, it's easy to get a veteran scout's face to light up by mentioning Brien Taylor. —Kevin Goldstein

8. Dave Dravecky
The San Francisco Bay area had a momentous year in 1989. The 49ers steamrolled through the NFL, former Oakland A's batboy M.C. Hammer introduced the world to parachute pants that could not be touched, and both of the local baseball clubs won their respective leagues to meet in an October Classic that will forever be remembered as the series that rattled a nation. Amidst such turbulent times, perhaps no player had a more arduous journey than Giants pitcher Dave Dravecky.

Dravecky's 1988 season was cut short when a cancerous tumor was found in his throwing arm, putting the southpaw's playing career in jeopardy at age 32. He underwent surgery in October of '88 to purge the malignant mass, a procedure that required the removal of half of the deltoid muscle from his throwing arm. Doctors told Dravecky that he would likely never pitch again, but he persevered through an exhaustive rehabilitation to overcome the odds. The left-hander returned to a major-league mound less than one year removed from surgery, tossing eight strong innings in his comeback appearance versus the Reds on August 10, 1989. His next start came five days later against the Expos in Montreal, and in the fifth inning the miraculous story suddenly turned into a horrific spectacle. The humerus bone of Dravecky's left arm snapped, mid-pitch, during a fastball delivery to Tim Raines. The hurler crumpled to the ground, writhing in pain. Dravecky would never throw another professional pitch.

Dravecky was in the dugout two months later when the Giants clinched the pennant, yet catastrophe struck again when his balky left wing was re-injured during the celebratory aftermath. Follow-up x-rays found yet another malignant tumor in Dravecky's throwing arm, indicating that the cancer had returned and effectively ended his career. The condition of the limb would deteriorate to such an extent that his prized pitching arm had to be amputated in June 1991, and though many people would be permanently crushed by such a tragic series of events, the heroic Dravecky responded by carving out a new career as a motivational speaker. —Doug Thorburn

9. Roy Campanella
Campanella's career began in 1937, at age 15, in the Negro Leagues. He spent parts of nine seasons there, mostly with the Baltimore Elite Giants, also making appearances with the Monterrey Sultans of the Mexican League in 1942 and 1943. Branch Rickey signed Campanella to play for the Dodgers in 1946 and sent the young catcher to the minors. Campy was recalled to Brooklyn during his third minor-league season after he hit .325/.432/.715 in 35 games at St. Paul in 1948. He performed well for the Dodgers at age 26, and only got better from there. In his prime, a seven-year stretch from 1949 to 1955, Campanella hit .288/.370/.531 with 200 homers and won three NL MVP awards.

Due to advancing age and a series of hand injuries, his offensive game slipped in 1956 and 1957, but Campanella remained a steady presence and team leader. Then, in January 1958, he lost control of a car he was driving on an icy street and crashed into a telephone pole. Campanella broke his neck and damaged his spinal cord in the accident, which left him paralyzed from the chest down. His baseball career was over, and he would spend the rest of his life in a wheelchair.

Campanella was inducted into the Hall of Fame in 1969. The New Bill James Historical Baseball Abstract lists Campanella as the third-best catcher ever to play the game, behind only Yogi Berra and Johnny Bench. —Geoff Young

10. J.R. Richard
J.R. Richard, quite sadly, has been pretty much forgotten over times. When pundits talk about the most dominant pitchers of the last half-century, his name is rarely mentioned. However, for a five-year period from 1976-80, he was as fun to watch as any pitcher. At 6-foot-8, he was a giant for those times, and what made him even more intimidating was that he didn't always know where his high-90s fastball was going. Richard could issue five walks in a game just as easily as he could register 10 strikeouts until he began to gain control of his pitches in 1978. He struck 303 batters that season and 313 the next.

In 1980, he was on his way to a potential season for the ages, going 10-4 with a 1.90 ERA and 119 strikeouts in 113 2/3 innings in his first 17 starts. Then tragedy struck. During an off-day workout at the Astrodome, Richard was felled by a stroke and nearly died. His body never fully recovered, and his career was over at 30. Would Richard have wound up in Cooperstown? Sadly, we'll never find out.—John Perrotto

​Thanks to Bradley Ankrom for research assistance.