I recently attended and participated in the 44th World Open in Philadelphia. Long a major summer event, the World Open offers the largest prize fund of any open Swiss in the world (this year, it was $225,000 guaranteed). The event was started in 1973 by New York City master Bill Goichberg and his organization, Continental Chess Association (www.ChessTour.com).

The 1975 version with 815 players, including five grand masters and one international master, was witness to perhaps the greatest upsets in chess history when 19-year-old Brookline High grad and Dartmouth College student Alan Trefler, an expert (2045) with a lowly tournament ranking of 115th, tied for first with the famous grandmaster Pal Benko. (Trefler is now the CEO and founder of Cambridge software company Pegasystems.)

Over the years, the event has been in many places, but primarily it has been in Philadelphia over the July 4 weekend. The tournament was very well run with a large and well lit playing room. Since the open section was a FIDE event, signed score sheets were collected after each game. The tournament has started using DGT boards (www.DigitalGameTechnology.com) and MonRoi devices (www.MonRoi.com) to broadcast some Open section games over the Internet.

The 44th version had 1,223 players in nine sections, with 221 in the Open section. There was seven-way tie for first, with each winning $5,800 (for full results, go to ChessEvents.com/WorldOpen/). The top two finishers, determined by a tie-breaking formula, Gabor Papp and Victor Bologan, played an “Armageddon’’ game to decide the tournament winner. Papp won the game and an extra $500.

I finished with 5.5 points, losing 1 rating point but winning $214.29. Sadly, there were surprisingly few Massachusetts players. My unofficial count gave only 22 in the whole tournament which must be an all-time low. Sam Sevian scored the highest of our contingent with 6.5 points.

Winners: Waltham CC Summer Open: 1st: David Martin, 8.5-1.5; Vortex CC: 1st: Calvin Hori, 5-1; Boylston Tornado #124: Open: 1st: Denys Shmelov, 4-0, U1950: 1st–2nd: Bret Zeldow, Charles Bing, 3.5-.5.

Coming events: Waltham CC Blitz Championship, July 22 and 29, Waltham CC, 404 Wyman St., Cafeteria, Waltham, www.WalthamChessClub.org ; 66th New Hampshire Open, July 23-24, Radisson Hotel Nashua, 11 Tara Blvd., Nashua, www.NHChess.org.

Answer to today’s problem: 1.Bxe5! (Winning a piece) fxe5 2.Qd5+ Qxd5 3.Nxe7+ Kg8 4.Nxd5

Today’s problem

Chris Chase can be reached at BostonGlobeChessNotes@Gmail.com.