They don’t know if the bass will still be lingering in the shallow to midrange depths after the spring spawn, or if they’ll be in their summertime deep-water haunts.

The pros only seem sure of one thing: Some giant bags of fish will be caught.

The tournament — which is an exciting meld of the popular Texas Toyota Bass Classic (TTBC) held the past 10 years and the BASSfest event that has recently exploded in popularity — is scheduled for May 17-21.

A full field of 109 anglers will compete Wednesday and Thursday, with only the Top 51 advancing to Friday’s semifinal round. The competitors will take a day away from the lake Saturday for seminars, boat demos and an outdoors expo.

The Outdoors Expo will take place at the George H. Henderson Exposition Center Friday through Sunday — for more information on times and a full list of vendors, please visit Bassmaster.com.

Companies activating will include the Toyota Ride and Drive obstacle course, open to qualified drivers 18 and over. Toyota is also sponsoring a CastingKids course that helps youngsters hone their skills in pitching, flipping and casting. Fishing families in the market for a new bass rig can take part in demo boat rides provided by Skeeter, Yamaha, Nitro, Triton and Mercury at Cassels-Boykin Park. A free shuttle for transportation will be provided between the Expo Center and the park.

The Texas Parks and Wildlife Outdoor Adventures Area on site will include activities for all outdoor sports enthusiasts including the Recreational Boating and Fishing Foundation’s Vamos a Pescar/Take Me Fishing Trailer where youngsters and their families can learn about boater education and important fishing techniques.

In addition, a “Get Hooked On Fishing” interactive children’s program will feature casting lessons, fishing in the Bass Pro Shops Catch & Release Pond, and a chance to meet bass pro and former NFL wide receiver Kendall Newson, founder of the Teach a Child to Fish Foundation. School children from the Lufkin Independent School District will be taking part in the activities as part of a special field trip opportunity on Friday.

The Top 12 anglers who make the final cut will resume competition Sunday with a $100,000 first-place prize and a berth in the 2018 GEICO Bassmaster Classic presented by DICK’S Sporting Goods on the line.

“That automatic Classic berth makes this tournament really special,” said veteran Florida pro and nine-time Classic qualifier Bernie Schultz. “You could really make your whole season by winning this event.”

How the event will be won is anyone’s guess.

Texas pro Kelly Jordon — a nine-time Classic qualifier and one of the founders of the Texas Toyota Bass Classic — thinks multiple methods could be responsible for giant catches.

“I really think it could be like the tournament we had on Toledo Bend (in 2016),” Jordon said. “In that tournament, Kevin VanDam finished first fishing a deep-diving crankbait offshore. Then Chris Lane finished second fishing a Whopper Plopper around shallow stuff.

“It could be a tournament where you can catch them just about any way you want to catch them — and it could be the kind of event that forces you to do something different every day.”

Jordon said the lake has the potential to produce numerous 30-pound bags if the timing is right. But regardless of where the fish are holding, he believes it will take an average of 20 pounds or more per day to win.

“There’s a lot of hydrilla in the lake,” Jordon said. “There’s plenty of grass to fish. There’s a lot of brushpiles. The lake has got a lot of offshore structure. There’s a lot of shallow, flooded bushes.

“People will be able to pick and choose — and I think a lot of people will really mix it up.”

Brandon Card — a Tennessee angler who is fresh off a 16th-place finish on Mississippi’s Ross Barnett Reservoir — agreed with Jordon that it could take some mixing and matching to put together a winning bag.

“I know there are some people who have their ideas about where they’ll be,” Card said. “But no one will be able to say for sure until we get there for the official practice days (May 14-16). I think it’ll be very important to show up with an open mind.”

Besides the unusual Wednesday start — most Elite Series events start on Thursday — and the day off on Saturday, the tournament will feature another first-time rule distinction in an Elite Series event. Instead of bringing five fish to the scales, anglers will have their fish weighed immediately on the water by official judges, and they’ll be released without ever going in a livewell.

B.A.S.S. has used the catch-weigh-release format once before, for last year’s Classic Bracket event on the Niagara River in Buffalo, N.Y., but that event only featured eight anglers, while this one will have a full Elite Series field.

Anglers will be allowed to bring in one fish at least 21 inches long to show to the crowd at the weigh-in.

“This is a great event benefiting Texas Parks and Wildlife and their efforts to introduce people who live in urban areas to fishing,” Jordon said. “It’s also a great opportunity for the Bassmaster Elite Series to showcase the quality of the fishing in Texas.

“Even with the catch-weigh-release format — which is an unbelievable idea that originated with the TTBC — people are going to see some really big fish brought to the scales.”

Daily takeoffs will be held at 7 a.m. CT from Cassels-Boykin Park in Zavalla, Texas. Weigh-ins will be held at 4:30 p.m. at the George H. Henderson Jr. Expo Center in Lufkin.

The event is hosted by the Lufkin Convention and Visitors Bureau.

2017 Toyota Bassmaster Texas Fest Platinum and Title Sponsor: Toyota

2017 Bassmaster Elite Series Premier Sponsors: Huk, Humminbird, Mercury, Minn Kota, Nitro Boats, Power-Pole, Shell Rotella, Skeeter Boats, Triton Boats, Yamaha, Berkley

2017 Bassmaster Elite Series Supporting Sponsors: Livingston Lures, Lowrance, Phoenix Boats, Shimano, T-H Marine, Advance Auto Parts, Academy Sports + Outdoors, Carhartt, Dick Cepek Tires & Wheels

2017 Toyota Bassmaster Texas Fest Beneficiary: Texas Parks and Wildlife Department