Welcome back, RotoBallers! The first half is over and adjustments must be made in order to prepare for the stretch run. Obviously, batting average is one of the key statistics fantasy owners value, but contact rate can also be telling of all-around success at the plate. A sudden increase or decrease in contact rate could signal the beginning of an extended hot or cold streak, leading to important waiver wire choices or start/sit decisions for fantasy baseball managers.

Each week we will look at a few players who are rising and falling in terms of contact and compare their previous week's contact rate with their season-long performance.

Here are some of the top contact rate risers and fallers for Week 15 of the fantasy baseball season.

Contact Rate Risers

Nelson Cruz (OF, SEA) 87% contact rate last seven days (+15%)

When he's not taking selfies with umpires, he's crushing the ball at a high clip. Cruz has raised his batting average to .292 on the season, proving again that he's more than just a slugger. The Mariners may not be going anywhere this season, but neither is Cruz. Despite his advanced baseball age (37 years old), he's shown no signs of decline whatsoever.

Mallex Smith (OF, TB) 89% contact rate last seven days (+14%)

After a hot streak immediately upon activation from the disabled list June 9 (coinciding with Kevin Kiermaier hitting the shelf), Smith then slumped a bit. He went two weeks without a steal and earned himself a couple of days out of the starting lineup. Since then, he's picked back up where he started. Smith has 11 hits in his last 25 at-bats and is hitting .500 in the last seven days. He is stealing a base almost once every three games, so even if his average declines, he is still worth owning in nearly all mixed leagues.

Nomar Mazara (OF, TEX) 90% contact rate last seven days (+14%)

It's unclear whether the Rangers will turn things around, as they may even be forced to become sellers at the deadline. Mazara remains one of the young centerpieces of the team and has a somewhat favorable hitting environment, so it's too soon to give up on him for 2017. Mazara is hitting .258, which isn't helping too many fantasy teams at the moment. Although his contact is improving, he's only eight points behind last year's season-end average and right around his minor-league numbers in the category. He's only 22 and has oodles of potential, but maybe it's time to temper expectations that he will suddenly break out.

Manny Machado (3B/SS, BAL) 88% contact rate last seven days (+11%)

It could have come a lot sooner for those who spent a first or second-round pick on the young star, but he could be showing signs of a second-half surge. Machado hit .355 in the week before the break, bringing his average to a still-paltry .230 on the year. The power numbers are still pretty good (18 HR, 47 RBI, .445 SLG), but the fact he's absent from All-Star weekend is shocking and telling of how he's struggled to get on base at times. His .239 BABIP is bound to rise and his plate discipline isn't much worse than previous seasons. There's still a buy-low window here, so act fast before the second half gets underway.

Contact Rate Fallers

Hunter Renfroe (OF, SD) 49% contact rate last seven days (-20%)

Renfroe profiled as a much better contact hitter in the minors, but he looks like a pure slugger so far in the bigs. Renfroe has 16 home runs in the first half, but is batting just .231 with a .287 OBP. Those numbers have fluctuated quite a bit, though. His OBP by month: .231 in April, .358 in May, .270 in June. Aside from his recent slump, if you need another reason to sit Renfroe on the bench (or send him to waivers), he left Saturday's game early with neck stiffness. It shouldn't result in a DL stint, but as the numbers show, it's been an up-and-down season already for the rookie. He doesn't figure to help your averages this season, so play him in deep leagues for power only.

Logan Morrison (1B, TB) 59% contact rate last seven days (-18%)

Let's be honest, you don't care what LoMo's average is anyway. He's a career .246 hitter and is barely outperforming that with a .258 season average. The draw is that he's already set a high mark with 24 HR and has been a revelation off the waiver wire. Truth be told, his contact rate decline is a bit misleading. He went 0-for-10 in the three games before the break, but he was 8-for-14 in the four games before those. If he goes a couple weeks without going deep, then you should start worrying.

Cameron Maybin (OF, LAA) 65% contact rate last seven days (-12%)

Maybin was a prime regression candidate heading into this season, if ever there was one. He hit .315 in half a season's worth of action for Detroit last season, but never hit higher than .267 in seven previous full seasons. His .245 average this season is about right, but he's walking 13.3% of the time which is four points higher than last year's career-high. If this holds up, which may be hard to count on, he'll keep stealing bases at a high rate and delivering solid value. In this case, don't focus on average so much as on-base percentage.

Justin Smoak (1B, TOR) 71% contact rate last seven days (-10%)

It's not a huge drop, but Smoak is another player who is vastly over-performing compared to his career norms. There isn't a category where his current numbers don't appear to be a huge outlier in a mostly disappointing career, but his average is probably the most surprising. Smoak is currently hitting .294, which is a stark contrast to last year's .217 and the previous year's .226 in Toronto. Is last week's 10 percent drop in contact rate a sign of inevitable decline the rest of the way? I'd like to say no, but if you're able to sell high for an established star, now's the ideal time.

More Risers and Fallers