Can ‘Jeopardy!’ whiz James Holzhauer be beaten? The science of memory and recall, explained.

Yes, he knows an encyclopedia’s worth of facts.

Yes, he will bet north of $20,000 without flinching.

And yes, he seems to hit the game buzzer with the reaction time of an Olympic sprinter.

But none of this would matter in the success of Jeopardy! champ James Holzhauer without one additional talent: the ability to retrieve information quickly from his brain.

Holzhauer, whose next game airs Monday, summons facts from his memory with such speed that few contestants have come close to beating him. He has raked in $1.69 million in 22 games that have aired to date, winning money at the fastest clip in the show’s history.

What will it take to topple the champ?

A few basic strategies can help anyone become faster at remembering facts, say psychologists who study memory and learning. Study after study has identified ways to make memories more durable and accessible, and those benefits tend to go hand-in-hand with greater speed, said Michael J. Kahana, a University of Pennsylvania professor of psychology.

But those who would slay the game-show giant should beware: In an interview via email, Holzhauer said he has used some of these tips himself.

Each time a person learns a piece of information, it is not stored in the brain in isolation, Kahana said. Instead, it is wrapped up in context: how it was acquired (reading a book, watching TV) and the way it was presented (learning about Napoleon as part of a lesson on battlefield tactics, say, or in the context of studying imperialism). The context of a memory also includes unrelated details such as the learner’s location and what else he or she was thinking about at the time.

So the key to learning something beyond a trace of a doubt is to overlearn it — reinforcing the knowledge by exposing yourself to it in a variety of contexts, Kahana said. That way, when you are asked to retrieve it, there is a better chance that the way the question is phrased will match something about the way you stored the information.

“The better the match, the faster the retrieval,” Kahana said.

Holzhauer has described how he read children’s reference books to prepare for the show, saying their easy-to-digest format allowed him to cover a wide range of material. But it also would have helped in the way Kahana describes: reinforcing knowledge that the champ had acquired previously in some other fashion.

Learning material in more than one context also can help the brain organize it, said Michael K. Gardner, a professor of educational psychology at the University of Utah. That allows for more efficient retrieval, quickly narrowing down a wide array of possibilities (historical figures — military leaders — France — Napoleon!) instead of going through a list of facts one by one.

“The more you have information organized, the fewer direct links you need," Gardner said. "If you had to do a random search of everything in your memory, it would take you a long time to get to the answer.”

Finally, the key to solidifying the acquired knowledge is to test yourself. Passive reading is not enough.

Holzhauer, a professional sports bettor who lives in Las Vegas, shared few details in his email, but agreed that overlearning and self-testing made sense.

“I would definitely say I applied those two strategies in my studies,” he said.

It’s no secret that certain brain functions decline with age, among them reaction time, and at 34, Holzhauer is close to his prime.

Ken Jennings, who still holds the records for most Jeopardy! victories and the amount of regular-season winnings, told Wired magazine that during his championship run, he was about as good as Holzhauer in his ability to summon facts quickly. But if he were to go up against Holzhauer now? He has doubts.

“That’s not me, that’s Ken from 15 years ago, who was 29, still super mentally acute," Jennings said of his appearances on the show in 2004. "It’s kind of a young person’s game.”

However, age need not be a total roadblock, as Kahana and colleagues found in a 1998 study conducted at Brandeis University.

Two groups of people, average ages 19 and 71, memorized a list of 25 words in five categories, then were asked to recite them in any order. The researchers measured how long each person took between items, comparing participants with similar levels of accuracy.

Young and old were equally fast when jumping from item to item within the same category (car-truck-train or corn-peas-beans).

But when switching categories (going from, say, truck to corn), all participants needed at least another second or two between reciting one item and the next. And on average, the older participants slowed down more than the younger ones.

On Jeopardy!, the same should hold true, Kahana said. When consecutive clues come from the same category, the effects of age should be negligible. But a younger contestant can get an edge by jumping from category to category. That is what Holzhauer does, though he does so for a different reason — trying to win all the higher-value clues early in a game so he has more money to wager if he lands on one of the coveted Daily Double squares.

Kahana said anyone, young or old, could improve performance in a given category by thinking in advance of items that fit. So Alex Trebek is asking for Broadway songwriters? Prime your brain by thinking ahead about Gershwin and Sondheim, along with more recent notables such as Lin-Manuel Miranda and Elton John.

Once again, Holzhauer is on board — to a degree. The game moves too fast to engage in much of this type of brain-priming, but the champ confirmed that he has done it when appropriate.

“Only for Final Jeopardy (and only for relatively narrow categories like “European Capitals”) as I felt it would be too distracting at any other point,” he said.

Speed pays dividends on Jeopardy! in several ways. The contestant who hits the buzzer fastest gets first crack at responding to a clue. And if he or she gives the correct response, the contestant gets to pick the next category. The more opportunities to pick a category, the greater the chance of uncovering a Daily Double — allowing contestants to bet any amount up to their entire stash, as Holzhauer sometimes has done.

Kahana hypothesized that speed is at such a premium that it may make sense for a person to hit the buzzer even before being completely sure of knowing the correct response.

“If the cost for a mistake is small relative to the opportunity cost for not having gotten to give the correct answer, you’d want to be more liberal in how willing you are to make a mistake,” he said.

Holzhauer agreed, and confirmed that he has done so.

“You have seen me miss some questions, right?” he said.

But at what point does it make sense to trade a bit of certainty for speed? Should contestants go for it if they are 90 percent certain they know the right response? 75 percent?

The tipping point may be lower than casual viewers realize. As devout Jeopardy! fans know, contestants do not necessarily need deep knowledge of a subject area in order to give the correct response. The clues frequently contain hints, and the correct response may simply be the obvious one. If the clue mentions something about a French general and the 19th century, it is a safe bet that the right response is “Who is Napoleon?”

Here again, there may be a way for older contestants to negate some of the effects of age.

Though humans’ speed of information recall slows a bit with age, they continue to acquire knowledge throughout most of their lives, said Gardner.

“That’s why when you’re 75, you’ll be able to do the New York Times crossword puzzle,” Gardner said.

So if a Jeopardy! contestant feels very confident in a certain category, it may make sense to hit the buzzer no matter what, because the person then gets a few more seconds to say the response. The correct response may take a moment to materialize, but it is likely in there somewhere — especially given that contestants are prescreened for having a wide knowledge of trivia.

Someone would need to put all this together in order to beat Holzhauer, coupled with a hefty dose of luck. Will it happen anytime soon?

Tune in Monday.