There is one sort of baseball rivalry that can spring up at any moment.

A pitch that goes up and in on a batter, a hard slide at second base, or a player taking his time to admire a big home run -- all of these things can turn up the heat between two teams over the course of a game or season. At times, things can boil over and turn any ensuing matchup into a melee waiting to happen.

Then there are the rivalries of circumstance. Two teams become powerhouses at the same time and find themselves battling each other for supremacy year after year. Familiarity breeds contempt.

Finally, there are those few ever-present, iconic rivalries that stand the test of time.

On the East Coast, it’s Red Sox vs. Yankees. In the Midwest, it’s Cardinals vs. Cubs. And on the West Coast (at least, since the 1950s), it’s Dodgers vs. Giants.

Each is long past the point when the circumstances dictate whether a particular game is important. When these pairs meet up, it’s always important, especially for the fans.

Of course, context still matters. Each pair shares a five-team division and competes every year for a division title that guarantees a berth in the playoffs, so that helps keep the fires burning. If both clubs are good, and have long-tenured players with a personal stake in the rivalry, all the better. If there are players who have changed allegiances, or some sort of simmering bad blood exists over a past dispute, watch out.

There are of course other good rivalries across baseball, but these three have been percolating for well over 100 years apiece and stand as prime examples of the history and passion that help provide the backbone of the sport.

Red Sox vs. Yankees
Results through 2018: Yankees 1,189-991 (since 1903)*

Back when this all began, New York was known as the Highlanders, Boston was known as the Americans, and Babe Ruth was eight years old. And it was Ruth who put the first big log on this rivalry’s fire, when New York purchased the pitcher-outfielder from Boston after the 1919 season. To that point, Boston was the behemoth, winning five of the first 16 World Series. But along with Ruth shifted the balance of power. The Red Sox infamously didn’t win another championship between 1918 and 2004, an era marked by the so-called “Curse of the Bambino,” to account for Ruth’s influence. Meanwhile, between 1921-64, the Yankees went to the World Series an incredible 29 times, winning 20. They have since taken their all-time record total to 27.

Over the years, this rivalry has featured many iconic players, from Ruth and Lou Gehrig, to Joe DiMaggio and Ted Williams, to Mickey Mantle and Carl Yastrzemski, to Derek Jeter and David Ortiz, to (now) Aaron Judge and Mookie Betts.

It’s had its signature moments as well. The Yankees’ Bucky Dent forever attached his name to a curse word among New Englanders with his home run that sent New York to victory in a tiebreaker game that decided the American League East championship in 1978. New York’s Aaron Boone did the same in the decisive Game 7 of the 2003 AL Championship Series that sent the Yankees back to the World Series. But in the next year’s rematch Boston overcame the Yankees to become the only team to rally from a 3-0 deficit to win a best-of-seven playoff series.

Cardinals vs. Cubs
Results through 2018: Cubs 1,230-1,171 (since 1892)*

These franchises have been battling since St. Louis joined the National League in 1892, separated by only 300 miles of highway and competing for the affections of fans throughout a huge swath of territory in the middle of the country. The Cubs won the World Series in 1907 and ‘08 before running into a championship drought of their own, one that ultimately stretched on longer even than Boston’s, until Chicago finally triumphed in 2016.

In between those two points, the Cardinals largely played the big brother role, even as the Cubs held the edge in the head-to-head-series. St. Louis ranks second only to the Yankees with 11 World Series titles, and from the formation of the NL Central division in 1994 through 2015, won the division 10 times, to three for Chicago. The Cubs have enjoyed the upper hand since.

Perhaps the most famous time in the rivalry’s history had little to do with wins and losses. That was in 1998, when the Cardinals’ Mark McGwire and the Cubs’ Sammy Sosa captivated the entire country with their co-pursuit of Roger Maris’ single-season record of 61 home runs, set for the Yankees in 1961. After dueling all year, McGwire got there first and finished with a (since-broken) record of 70, to 66 for Sosa.

Dodgers vs. Giants
Through 2018: Giants 1,249-1,221 (since 1890)*

The Dodgers joined the Giants in the NL in 1890, though they went through a few other names (Bridegrooms, Superbas, Robins) before settling permanently on Dodgers in the 1930s -- a reference to the dangerous trolleys of Brooklyn, where the team then played. The Giants were across town, in Manhattan, giving New York three teams. That all changed after the 1957 season, when the Dodgers moved to Los Angeles and convinced the Giants to join them on this westward expansion, heading to San Francisco.

The move, and geography, helped solidify the rivalry. Both teams have enjoyed their own boom times over the years, with the Dodgers leading 24-23 in league pennants but the Giants 8-6 in World Series, after winning three between 2010-14.

Iconic players such as Jackie Robinson, Willie Mays, Sandy Koufax, and Barry Bonds have lent an extra shot of energy to the proceedings. So have some iconic moments. Although the two franchises have never met in an official postseason game, they played a three-game tiebreaker to determine the National League champion in 1951. The final game was decided on Bobby Thomson’s “Shot Heard ‘Round the World” -- a homer that won it for the Giants and spawned one of the most famous radio calls in sports history, Russ Hodges’ repeated cry of, “The Giants win the pennant!”

*Records exclude ties.