Every sport has records that are virtually guaranteed to remain forever. Think Cal Ripken Jr.’s consecutive games streak in Major League Baseball. Tennis has records like this, too. Here are seven records in the sport that you’ll likely never see broken.

Fastest serve recorded: 163.4 miles per hour

Samuel Groth isn’t a household name, but the Australian holds a tennis record that won’t be broken any time soon. He is credited with a serve that clocked in at 163.4 miles per hour during a match in South Korea. Despite landing in the record books, Groth lost the match to Belarusian Uladzimir Ignatik in straight sets (4-6, 3-6).

Longest consecutive run as men’s world No. 1: 1,659 days

You’re probably waiting for Roger Federer’s name to appear with one of these records. Well, here it is. The Swiss legend holds the record for most consecutive weeks atop the men’s world rankings. Federer spent 237 straight weeks as the world No. 1, a run that began on February 2, 2004 and ended on August 17, 2008 — a span of 1,659 days.

Most wins at a single Grand Slam: 12

Winning a single Grand Slam tournament is an accomplishment few tennis players experience. Winning multiple Grand Slams is even rarer. So imagine how unusual it is for one athlete to win 12 Grand Slams — all at the same event. That’s what Rafael Nadal has done, claiming victory at the French Open a dozen times, including the last three years.

WTA singles titles: 167

The Women’s Tennis Association is the top tour on the women’s side of the sport, so winning any WTA title is a feat. This means Martina Navratilova was proud of herself 167 times — the amount of WTA singles titles she won in her storied career. To put that into perspective, Serena Williams, widely considered one of the best female tennis players ever, has 72 career WTA titles to date.

Longest match-winning streak: 74

Navratilova holds this record, as well, among both men and women. In 1984, she won 74 consecutive singles matches, which is a record in the Open era. Putting that into perspective, Bjorn Borg holds the record for men at 49 consecutive singles matches, which pales in comparison to Navratilova’s success. With the competition on the tennis circuit today, it’s unlikely anyone will be able to match, let alone surpass, Navratilova’s streak.

Longest match: 11 hours, 5 minutes long

In 2010, Wimbledon served as the venue for the longest match in tennis history. John Isner beat Nicolas Mahut in an epic five-set battle that took 11 hours, five minutes to complete. The first-round match actually had to be played over the course of three days. Unsurprisingly, Isner lost in the next round, likely due to exhaustion from the marathon match before.

Rackets smashed in a season: 48

This isn’t as illustrious as the other records we’ve discussed, but it’s a record nonetheless. Marat Safin, a two-time Grand Slam champion, is credited as smashing the most rackets in a season. In 1999, he broke 48 rackets during match play, a record that still stands 20 years later.