Pete Alonso is having a rookie year for the ages. He is on pace to challenge Aaron Judge's rookie record of 52 home runs. Heading into the second half of the season. Alonso's first half numbers would be a great entire season for more big leaguers. He has 30 HRs and 68 RBIs thru just 89 games.
Fernando Tatis Jr is second to Alonso currently. Alonso would have to completely fall off the edge of the Earth not to take home rookie of the year honors.