In what has become a year-end tradition, MLB.com takes a look back at the top storylines of the year -- the Top 15 for 2015.
To say that Commissioner Rob Manfred's first year in office was busy is kind of like saying Mike Trout is a pretty good player -- an understatement.
Since succeeding Bud Selig and becoming the 10th Commissioner in the history of Major League Baseball on Jan. 25, Manfred has both honored the course set by his predecessor and put his own stamp on the office.
"I've had a year full of really exciting days," Manfred said recently.
:: 15 for '15 ::
Manfred's most personal efforts have involved youth initiatives, which he has made clear are a priority.
In June, MLB and USA Baseball launched the Play Ball program, which is designed to encourage widespread participation in baseball and softball activities among all age groups. In July, MLB and the Major League Baseball Players Association announced a joint youth development initiative to support key baseball and softball programs designed to improve access to the sport across the U.S. and Canada.
At the Winter Meetings in December, Manfred named Hall of Famer Cal Ripken Jr., chairman and founder of Ripken Baseball, as his special advisor to the Commissioner on youth programs and outreach. All are part of Manfred's efforts to unite MLB with various organizations such as the Minor Leagues, Little League, USA Baseball and the NCAA under the banner of One Baseball.
The goal is not only to help grow the sport, but to advance player safety and create more seamless scheduling and messaging throughout the sport.
"[The most enjoyable part] is actually something I got to do earlier," Manfred said at the World Series. "I did a visit at one of the Boys & Girls Clubs here in Kansas City. They had a Play Ball event ... and the kids got an opportunity to interact with the game and it was really fun to see how much they enjoyed the game. It's really been the favorite part of my first year."
In addition to presiding over his first All-Star Game and World Series, and helping induct new Hall of Famers for the first time, Manfred also met with each MLB team and awarded All-Star Games to San Diego (2016), Miami (2017) and Washington (2018).
Continuing the international growth of the game ranks high on Manfred's agenda, too, so he traveled to Mexico for talks with baseball officials in that country about developing a closer working relationship. His long-range vision for expansion could include Mexico City or Montreal. And a contingent of big leaguers recently concluded a goodwill tour to Cuba with the possibility of exhibition games on the island as early as this spring.
In April, Statcast™ premiered. It's a giant technological leap forward that allows fans to follow to access inside baseball such as route efficiency for outfielders and the "exit velocity" of the ball off the bat.
In August, MLB announced a landmark domestic violence policy.
"I think the key from our perspective was being proactive and negotiating what we see as a comprehensive policy with the MLBPA. So everybody knows how the process is going to work. How we're going to move forward together," Manfred explained. "I think the second word I'd like to emphasize there is comprehensive. This is not just a discipline policy. It is a policy that requires evaluation, counseling, a variety of other activities in addition to the disciplinary component."
In November, MLB struck a three-year deal with FOX that will allow fans to watch live in-market streaming on any mobile device. This agreement currently covers only 15 teams, but Manfred said negotiations continue with the rights-holders for the remaining markets and he would like to have all teams covered next season.
"The media landscape is changing very, very rapidly; it's important for us to make certain our content is available on as many platforms as possible in ways that fans may want to enjoy our games," Manfred said. "And I think this is a huge step forward for the industry. I really do."
On the executive side, new recommendations for safety netting were issued and possible tweaks on instant replay and rules governing slides into second base were studied and prepared in advance of negotiations on a new Collective Bargaining Agreement that will begin in the spring. Manfred also met with Pete Rose and, ultimately, denied Rose's permission for reinstatement.

"And one of the things that's at the top of my list, I want to continue to make progress on the issue of pace of game," Manfred said. "We got off to a great start this year. We knocked six minutes off the game time. But I think it's important that we try to keep the momentum up and continue to make the games as tight as we possibly can."