Hold your horses: The most exciting two minutes in sports is set for Saturday at Churchill Downs when the 143rd running of the Kentucky Derby gets underway. The field of 20 horses is set, but the odds are always shifting, even up until the starting gun at 6:46 p.m. ET local time on NBC.

Where should you put your money this year? We consulted Mark Coomes, a betting expert and horse handicapper who previously wrote about the sport for the Louisville Courier-Journal and has attended every Kentucky Derby since 1979.

Coomes knows what he's doing, so now you can too. Absorb this advice and cash in.

First, the field as of Friday morning, with post positions and odds.

1. Looking at Lee (20-1)
2. Thunder Snow (20-1)
3. Fast and Accurate (50-1)
4. Untrapped (30-1)
5. Always Dreaming (5-1)
6. State of Honor (30-1)
7. Girvin (15-1)
8. Hence (15-1)
9. Irap (20-1)
10. Gunnevera (15-1)
11. Battle of Midway (30-1)
12. Sonneteer (50-1)
13. J Boys Echo (20-1)
14. Classic Empire (4-1)
15. McCracken (5-1)
16. Tapwrit (20-1)
17. Irish Way Cry (6-1)
18. Gormley (15-1)
19. Practical Joke (20-1)
20. Patch (30-1)

***

1. Best way for newbies to bet: across the board

COOMES: It seems like most people grasp the concept of win, place, show and "across the board." That's betting two across the board on say, Classic Empire. That means you'll have two to win, two to place, two to show, so you're covered if he runs 1, 2 or 3. Over time, your profits are going to get killed by all the takeouts and percents. But across the board is a great way for newbies because it has a likelihood of returning some profit and giving them some encouragement and some money to play the next race. People get that pretty easily.

2. Be a no show

COOMES: You don't get enough money [betting on a horse just to show] to make it worth your while. You might as well go buy a beer or drop it on the floor, really. And most races, if the horses who are favored in the top 2-3 win, you're going to be lucky to double your money in a show bet. You bet two and get four back (including the original two). But with an across the board bet, you have the option for a baby bear, mama bear and Goldilocks. If your horse wins, you get all three and people's eyes really light up when that happens and that's fun to see.

3. Don't count on a sure thing this year

COOMES: The last three years, we've been blessed with real standouts. California Chrome and American Pharoah are going to go down as two of the best horses of this century, even though we have 83 more years to go. And Nyquist was a very good two-year-old champion who was in good shape, which doesn't always happen.

This year, most of the contenders have really only won one good race in their life. That's not usually what you see in a derby. There's a lot of uncertainty coming in. Even the horses I like most, I would say all five of them are 50/50-ish to either win or finish 15th, and I don't recall ever having a situation where I felt that way.

4. If you want to bet conservatively, go with Always Dreaming and Irish War Cry to win

COOMES: There are two horses I might consider 60/40 or 70/30. And that would be Always Dreamy and Irish War Cry. They're two of the three favorites. I think Always Dreamy will actually go off as the slight favorite over Classic Empire. But you know, in the derby, instead of getting 2-1 on a horse like Irish War Cry, or Always Dreamy or Classic Empire, you're getting 4-1, 5-1, 6-1. The best stock traders in the world don't get 6-1 [odds]. That's the other thing I teach the newbies. Don't get greedy. 20-1 looks great, but the percentage of 20-1 horses who win is very, very low. It's like 1.8 percent of the population. And you just have to realize, if you can put 10 bucks in the window and get 60 back, those horses have good value as long as they don't go below 4-1. I wouldn't play any of these horses at 4-1.

Those horses are reasonably good bets that are going to make a reasonably good return and you're going to feel good amount of hope at the gate, going into the race and through the race, and if they fall apart, well, you're like the rest of us.

5. If you want a longshot, go with Hence

COOMES: He won the relatively anonymous Sunland Park Derby in New Mexico. It's the race Mine That Bird ran second in before he won the Derby in 2009, but this isn't Mine That Bird. That outfit has pumped up their purse enough to get some decent horses. This little Grade 3 stakes has turned out to be what horseplayers call "a key race," which means the results of this race have translated powerfully to other races. 

Hence won the Sunland Park Derby by almost four lengths -- a powerful victory. The horse that came in second went to the Arkansas Derby and damn near beat Classic Empire, who's going to be the favorite. The horse who finished third just finished second by a head in the Illinois Derby. The horse that finished fourth went to the Bluegrass Stakes and trounced some of the leading horses at the time for the whole enchilada like McCraken and Tapwrit. I think Hence is a very reasonable bet. He's going to be at least 12-1 and probably more like 15 or 16. There aren't many times I feel good about a horse in that odds range, but I feel good about him, and he's definitely got a better than 1 in 17 chance to win the race. And that's all you're really looking for: A spot where the odds are in your favor. 

COOMES' FINAL PICKS

Win: Always Dreaming
Place: Hence
Show: Irish War Cry