McKay, McMahon lead Top 10 1B prospects

MLB Pipeline will unveil its 2018 Top 100 Prospects list on Saturday with a one-hour show on MLB Network at 8 p.m. ET. Leading up to the release, we look at baseball's top 10 prospects at each position.
It's time to move around the infield with MLB Pipeline's Top 10 by position lists, starting with first basemen. It's a position that has a certain profile associated with it, involving power and run production. Some on this list look the part already, others are more hit-over-power right now, with perhaps the need to show more extra-base ability to match that description.
It's quite a different list than a year ago, thanks largely to the 2017 Draft. Four of the top five on this year's list were taken in the first round, starting with the top spot. The Rays took Brendan McKay with the No. 4 overall pick in the Draft and while he's going to both hit and pitch in 2018, many see a permanent move to the infield in the future. Pavin Smith was also a top 10 pick, going No. 7 to the D-backs while Nick Pratto (Royals, No. 14) and Evan White (Mariners, No. 17) went in the teens. Pratto is the lone high schooler from that quartet.
:: Complete 2018 Top Prospects coverage ::
The Top 10

1. Brendan McKay, Rays More »
   
2. Ryan McMahon, Rockies More »
   
3. Pavin Smith, D-backs More »
   
4. Nick Pratto, Royals More »
   
5. Evan White, Mariners More »
   
6. Bobby Bradley, Indians More »
   
7. Pete Alonso, Mets More »
   
8. Ronald Guzmán, Rangers More »
   
9. Lewin Diaz, Twins More »
   
10. Matt Thaiss, Angels More »
    Top tools
    Hit: 60 -- McKay, Smith
    Both were called the best advanced college hitters in the 2017 Draft class by different scouts. Smith gets the slight pure hit tool edge mostly because of his plate discipline after walking more than he struck out in three years at Virginia and continuing that pattern during his pro debut (27 walks, 24 K's last summer).

Power: 60 -- Bradley
The Indians prospect has as much, if not more, raw power than anyone on this list and he's tapped into it consistently as he's moved up the ladder, as evidenced by his .499 career slugging percentage and an average of more than 26 homers per year in each of his first three full seasons of pro ball.

Run: 60 -- White
You don't see many above-average or plus run grades from this position, but White isn't your typical first baseman. He's athletic enough to play the outfield well, which did he for the U.S. National Collegiate Team.
Arm: 60 -- McKay
The guy's on the Top 10 LHP Prospect list after all, so this is a no-brainer. He throws 92-95 mph off the mound and the arm works well in the infield.
Field: 70 -- White
Here's the reason why the Mariners will let White develop at first rather than in the outfield. He has the defensive chops to be a Gold Glove-caliber player at the infield corner position in the future.

Highest ceiling: McKay
McKay is tied for the highest hit tool and has a 50 power grade, with a very, very good chance of reaching, if not surpassing, that in terms of production. And if he starts focusing only on hitting eventually? Look out.
Highest floor: Smith
With such an advanced approach at the plate, the combination of pure hitting ability, low strikeout rate and high walk rate, few doubt Smith will hit his way up to the big leagues. Just how much the power shows up will ultimately determine his ceiling.

Rookie of the Year candidate: McMahon
None of the others on this list are likely to see time in the big leagues to compete for top rookie honors. McMahon is ready to hit in Coors Field full-time, even if he has to move around the infield a bit to get at-bats for the time being.

Highest riser: Alonso
Alonso entered his first full season of pro ball nowhere near the Top 10 first basemen list, even though he had hit very well during his summer debut following his second-round selection by the Mets out of the University of Florida. But then he showed that wasn't an aberration and hit his way to Double-A, with very solid hit and power tools showing up.

Humblest beginnings: Bradley
Five of the 10 on this list are former first-round picks, but the Indians got Bradley in the third round of the 2014 Draft. He did get an above pick value bonus to sign, but he's moved gradually, one station at a time, through Cleveland's system to be knocking on the door now.
Most to prove: Thaiss
The 2016 first-round pick out of Virginia did make it to Double-A in his first full season, fulfilling the scouting report as an advanced college bat with 77 walks and a .375 OBP. But Thaiss will eventually have to prove that he has extra-base pop (he slugged .395) to fit the everyday first-base profile in the big leagues.

Keep an eye on: Gavin Sheets, White Sox
Chicago nabbed Sheets in the second round of last June's Draft after he topped the ACC with 21 homers and 84 RBIs in his junior season at Wake Forest. Larry Sheets' kid had a solid pro debut, mostly with full-season Kannapolis, and has the offensive tools to hit for average and power.