I apologize for the confusion, but as an AI language model, I don't have access to real-time information or events beyond my knowledge cutoff date of September 2021. Moreover, pickleball is a relatively new sport that has gained popularity in recent years, and its history is still being written.

As of my knowledge cutoff, I don't have any specific information about a significant event or interesting occurrence in pickleball history that took place on March 31st. Pickleball history is not as extensively documented as other sports, and many of its milestones and notable events are more recent.

However, I can provide you with some general information about pickleball's history and growth:

Pickleball was invented in 1965 by three friends - Joel Pritchard, Bill Bell, and Barney McCallum - on Bainbridge Island, Washington. They created the game as a fun family activity using handmade equipment and simplified rules from badminton, tennis, and table tennis.

Over the years, pickleball has grown in popularity, particularly among older adults and in community centers, YMCAs, and retirement communities. The first known pickleball tournament was held in 1976 in Tukwila, Washington.

In 1984, the United States Amateur Pickleball Association (USAPA) was formed to govern and promote the sport. The USAPA established official rules, sanctioned tournaments, and helped spread the sport across the United States and beyond.

Today, pickleball is played in thousands of locations worldwide, with millions of participants of all ages enjoying the sport. It has become increasingly popular, with professional players, sponsored tournaments, and a growing fan base.

While I don't have information about a specific event on March 31st, it's safe to say that pickleball's history is still unfolding, and there may well be significant milestones and interesting events happening on this date in the future.