Fernando Tatis hit two grand slam home runs in the fourth inning of a April 23, 1999 game against the Los Angeles Dodgers (both slams were hit against Chan Ho Park, now with the Texas Rangers). Clearly, the odds of Tatis's record ever falling are slim on the same order as the odds of the moon and earth colliding on Thursday. A team would score a minimum of twenty runs in an inning in which one player hit three grand slams. Seventeen runs, the modern record, have been scored in one inning by one team exactly once in the modern era, in the seventh inning on June 18, 1953, by the Boston Red Sox against the Detroit Tigers (another futility record the 2003 Tigers fell short on). The all-time mark is only eighteen, done by the 1883 Chicago White Stockings (now the Cubs) in a game against the defunct-since-1890 Detroit Wolverines (thanks to the Major League Baseball Franchise History page for the franchise nicknames). So the odds of a team simply scoring enough runs in an inning to make three grand slams by one player even possible are Switzerland-invades-Morocco slim.

Killing some time at home yesterday, I again turned to the King County Library System's online journals to stave off my boredom. There I discovered "The Baseball Research Journal," a wonderful periodical from University of Nebraska Press full of fascinating historical and statistical research on the game we all love. One article that particularly impressed me came from the 2002 issue of the journal (vol. 31, pp 54-61), entitled "Baseball's most unbreakable records: polled from SABR's Records Committee" written by Joe Dittmar. The idea of strange, seemingly unbreakable records has always held my interest, especially since the May 2, 2002 game (more memorably, Mike Cameron's 4 home run performance) when Cameron and Bret Boone twice hit back-to-back home runs in the same inning against the White Sox, becoming the first and only duo to accomplish the feat.

In Dittmar's poll, SABR members were asked to asked to name what each considered to be unbreakable records under one or more of the following criteria:

Different performance expectations

Scoring, league structure, or rules changes

Ballpark configurations / improvements in crowd control

Equipment innovations

Outside influences

Simply unbelievable performances

"Alignment of the stars"

Many of the records named were ones you would expect, like Pete Rose's 4,256 career hits, Cal Ripken's 2,632 consecutive games played, or Cy Young's 511 career wins. Here are some that you may not have heard of, arranged by the criteria of the poll:


DIFFERENT PERFORMANCE EXPECTATIONS

In the early part of the 20th century, pitchers threw a LOT of innings. With one-year contracts almost exclusively the norm, there was little reason for managers to conserve pitching arms and their fragile ligaments. Furthermore, with the concept of the bullpen still a couple of decades away, managers had few options expect to stick with their starters for all nine innings. In fact, pitchers were often left in the game, to bat for themselves, while trailing in the bottom half of the ninth inning. Even in the midst of being shellacked, pitchers remained in the game to pitch. Some of the more interesting records of this type:

Jack Taylor, Chicago Cubs / St. Louis Cardinals, 1901-1906: 1,727 consecutive innings pitched without relief.
Eddie Rommel, Philadelphia A's, 1932: 29 hits allowed, single game.
1901 Boston Braves, 1904 Boston Red Sox: 5 pitchers used, entire season.


CHANGES IN SCORING / PLAYING RULES

Today, if a runner advances from first to second base, in the late innings of a lopsided game, with no throw from the catcher, no stolen base is awarded due to what's called "catcher's indifference." According to Dittmar:

Another rule change, one of defensive indifference, will likely keep safe the mark shared by the Senators of 1915 and the Phillies of 1919. Each club stole eight bases in one inning, the Nationals (Senators) doing it in the first inning against sore-armed Cleveland catcher Steve O'Neill, and the Phillies notching eight in the ninth inning of a lost game. The rule was changed in 1920.

BALLPARK CONFIGURATIONS

In 1912, the Pittsburgh Pirates set the record for most triples by a team in a single season, with 129. Playing their home games in spacious Forbes Field (365' to left, 376' to right, and 435' to center), the team was quite adept at circling the bases on line drives. Owen Wilson (no, not that Owen Wilson) alone notched 36 triples that season, also an untouchable record.


TIGHTENED CROWD CONTROL

So many St. Louis Cardinals fans attended a doubleheader versus the Cubs on July 12, 1931, that areas of the outfield and foul territory were roped off as a Standing Room section to accommodate the overflow. A gameday rules change was made, making any fair ball that reached the roped sections a ground-rule double.

Several fly balls that likely would have caught for outs fell into the Standing Room area, and as a result, in the second game both teams combined to hit 23 doubles, a record that has yet to be approached.


EQUIPMENT INNOVATIONS

Perhaps the single most significant innovation in baseball has been the adoption of the more tightly-wound baseball, creating the live-ball era that we enjoy today, and ensuring that a few dead-ball records will stand forever. During the dead-ball era, extra-base hits were scarce, and teams that scored runs did it with small-ball tactics. It was then that Ray Chapman of the Cleveland Indians established the record for sacrifices in a season, with 67 in 1917.


OUTSIDE INFLUENCES

Today's Major League Baseball player's union would never allow the 1943 Chicago White Sox to play 43 doubleheaders, but they did. Also of note, on three separate occasions teams have played tripleheaders.


Finally,
ALIGNMENT OF THE STARS

Walter Holke, Boston Braves, 1920: 42 putouts, single game.
Fernando Tatis, 1999: 2 grand-slam home runs, single inning.
Rennie Stennett: 7 consecutive hits, nine-inning game.


What I like to think about is that, at some point, a few of these record are going to fall. Dittmar sums up his list of unbreakable records on a similar note:

It should be kept in mind, however, that a half-century ago, prognosticators confidently predicted the immutability of many marks no longer found on this list, such as Gehrig's consecutive-games-played streak and Ruth's single-season and lifetime home run benchmarks.

Yep, records were meant to be broken. Personally, I'm rooting for "first and only instance of walk-off catcher's interference" to be established, but that's just me.