Four stats that showed why baseball had to lower the mound after 1968

We live in a pitching-dominated era, with strikeouts on the rise and ERAs dwindling. For those that love low-scoring pitching duels, it's a dream come true. For others, especially those that miss the days of 12-10 swatfests, it leaves something lacking. 

However, it is nowhere near the landscape that baseball had after the 1968 season. On Dec. 3 that year, a Major League rules panel got together and voted to lower the mound from 15 inches to 10, shrinking the strike zone to the top of the knees to the armpit (rather than shoulders and knees) and to be extra vigilant against doctored baseballls. In the end, it worked, with offense jumping from an average of 6.84 runs per game to 8.14. 

It also made for some strange outliers along the way. Here are four of the stats that probably led to the change: 

1. Bob Gibson's 1.12 ERA

That's right -- the number that has probably been burned into your brain since you were a young child. This number is so outrageously low for a starting pitcher, it doesn't quite seem possible in the modern era. And while Gibson was a fine pitcher, who would have likely had an excellent ERA that season no matter what, his second-lowest ERA in his career was over a full run higher at 2.18. 

While it was a historically great season no matter how you slice it, Gibson's ERA+, which normalizes his home ballpark and accounts for league averages, was 258. In other words, Gibson's ERA was 158 percent better than the league average. While Gibson may have the lowest ERA of all-time, this ERA+ number ranks him sixth behind Walter Johnson, Dutch Leonard, Greg Maddux and Pedro Martinez. 

2. Seven starters had an ERA under 2.00

Remember the big deal we made about two starters finishing with ERAs below two in Cy Young winner Jake Arrieta and likely free-agent-piggy-bank-breaker Zack Greinke? Imagine having seven of them. While that number is only eleventh all-time, all the other seasons ahead of '68 came before 1917. (1909 has the record with a shocking 19 pitchers finishing the year with a sub-2.00 ERA.)

And while luminaries like Gibson and Luis Tiant are on the list, with a second-tier of strong starters like Sam McDowell and Tommy John, there are also pitchers like Denny McLain (career 101 ERA+, all while winning 31 games), Bobby Bolin (career 104 ERA+) and Dave McNally (career 106 ERA+). Those are fine pitchers each, but not necessarily record breakers. 

3. Carl Yastrzemski won the batting title ... with a .301 average

It wasn't unusual for Yaz to win a batting title. After all, including '68, he won three of them in his career and was coming off the title in 1967 when he hit .326. Not only was Yastrzemski's .301 average the lowest ever for a batting title winner, but he won the AL title by 11 points over Danny Cater. 

While Pete Rose won in the NL with a .335 average, he was one of the few exceptions. The Majors set the record for the lowest-ever batting average (.237) and second-lowest on-base percentage (.299, two points behind 1908).

4. Entire teams couldn't hit

Seven teams hit .230 or lower. The Yankees, as a team, hit just .214. Mickey Mantle, in his final season, led the team with a 143 OPS+, but hit just .237/.385/.398 as a 36-year-old first baseman.

The White Sox scored a meager 2.86 runs per game, with only one player reaching double-digit home runs: third baseman Pete Ward. And while he knocked out 15 homers, he also hit .216/.354/.366. The Dodgers and Mets weren't much better, averaging just 2.90 runs per game.

It wasn't pretty.