- Bats Right, Throws Right
- Height 6' 2", Weight 205 lb.
Chiarini debuted in Serie A1 as a 16-year-old with the IVAS team, going 0 for 3. He was 4 for 21 in 1998 and 2 for 14 in 1999, as a utility infielder.
In 2000, Chiarini played for the AZL Mariners and hit .313/.372/.358 with 15 runs in 24 games. Surprisingly, that performance did not earn him a return to the Seattle Mariners chain for 2001. Chiarini played mostly third base for the AZL Mariners, making him the first of three Italians to cover the position for that team in a six-year period. Giuseppe Mazzanti followed in 2001 and Alex Liddi in 2006.
Chiarini moved to right field in 2001 though he would again see significant action at third base some years after that. Overall, he was primarily a right fielder though. He hit .274/.337/.440 for Semenzato Casa d'Aste Rimini in 29 games in 2001 and .251/.348/.429 in 2002. In 2002, he stole 11 bases in 14 tries and scored 46 runs in 53 games. He was third on the champion team in runs, trailing former major leaguer Chuck Carr and longtime AAA player Jim Buccheri.
In 2003, Mario batted .288/.353/.569 with 10 homers and 40 RBI in 40 contests for Telemarket Rimini. He was sixth in Serie A1 in slugging percentage and third in home runs behind former big leaguer Luis de los Santos and Claudio Liverziani. With the Italian national team, he hit .500/.563/.643 in four games in the 2003 Baseball World Cup. In the 2003 European Championship, he hit .241/.405/.448 with 3 doubles, a homer, 6 walks, 5 runs and 8 RBI in 8 games. He had 12 putouts and one assist while making no errors in RF. He had Italy's lone home run of the tournament as they finished a disappointing 5th. For the event, he was second in RBI (two behind Bryan Engelhardt), tied for third in doubles (one behind Erik Pappas and Giovanni Pantaleoni), tied Engelhardt for 10th in total bases (13) and tied Branko Nenadic and Evert-Jan 't Hoen for 8th in walks.
Chiarini produced at a .295/.396/.430 clip in 2004 and stole 12 bases in 14 tries. He tied for 4th in the league with 5 triples. In the 2004 Olympics, Chiarini hit just .208/.240/.417 as Italy's starting right fielder. He still finished third among the team's regulars in slugging. He had a key error on a hit by Ariel Pestano in the 5-0 loss to the Cuban national team. He was 2 for 4 with two runs and a solo homer against Chih-Chia Chang in Italy's lone win, beating the Taiwanese national team 5-4.
In 2005, the outfielder hit .285/.358/.331 in an off-year for Rimini. The next season, he batted .318/.426/.486 and stole 12 bases in 13 tries. He was sixth in Serie A1 in average and tied Cole Liniak and Maximiliano De Biase for second in doubles (13, trailing Oscar Salazar for the lead). He was just 3 for 20 in the finals but Rimini won its third title during his career (they had won in 1999 when he saw little action). In the 2005 European Championship, he hit .200/.333/.250 and Italy got the Silver Medal.
Chiarini batted .306/.419/.417 in the 2006 Intercontinental Cup, playing every game in right field for the Italians. In the 2007 Serie A1 campaign, he hit .319/.398/.444. He tied for 11th in Serie A1 in average, was 12th in OBP and tied Amaury Garcia for 9th in slugging. Chiarini was voted (at www.baseball.it) as one of the three Serie A1 All-Stars for 2007, joining Juan Camilo and Leonardo Zileri. In the 2007 European Cup, he batted .455/.458/.682 with 5 RBI in five games to help Rimini finish third. In the 2007 European Championship, he batted .320/.320/.360 as Italy finished a disappointing 7th.
Chiarini hit .261/~.346/.609 for Italy in the 2007 Baseball World Cup, leading the team in RBI (6) and homers (2) and was second in slugging percentage. He was one of the top performers in Italy's upset of Team USA, going 2 for 3 with a walk, double and RBI in that game.
At the 2009 World Baseball Classic, Chiarini made a spectacular diving catch to rob Bobby Abreu of an RBI on March 7, 2009 in Toronto. In the process of doing so, Chiarini suffered an embarrassing wardrobe malfunction: Mario's belt split in half. After pridefully making his celebrated catch, Chiarini looked down to see that his belt had completely snapped apart. Red-faced and embarrassed, Chiarini took the broken leather belt-strap out of his pants and borrowed a belt from a teammate, looping the belt around his waist to hold up his pants.