I apologize, but I couldn't find any significant events or interesting things that specifically happened on April 29th in the history of pickleball. As an AI language model, my knowledge is based on the information available up until September 2021, and pickleball, being a relatively new sport, may not have had a notable event on this particular date in its history.

However, I can provide you with some general information about pickleball. Pickleball was invented in 1965 by three fathers - Joel Pritchard, Bill Bell, and Barney McCallum - on Bainbridge Island, Washington, as a way to entertain their children during the summer. The game is a combination of tennis, badminton, and table tennis, played on a badminton-sized court with a slightly modified tennis net, using solid paddles and a perforated plastic ball.

Over the years, pickleball has grown in popularity, particularly among older adults, as it is a low-impact sport that provides a good workout and social interaction. In 1984, the United States Amateur Pickleball Association (USAPA) was formed to promote and standardize the sport. Today, pickleball is played in all 50 states and many countries around the world, with thousands of tournaments held each year.

While I couldn't find a specific event for April 29th, the history and growth of pickleball is an interesting story in itself, showcasing how a simple backyard game can evolve into a beloved international sport.