Back in September, I asked if 2015 would be Andy Dalton's breakout year. About half of you said it would. The other half either considered 2013 his breakout year or didn't see why things would change dramatically.

As it turns out, Dalton took a huge step forward. Let's look back on some of Dalton's best throws and his three fourth quarter comebacks:

Dalton set career highs in QB Rating (106.3), yards per attempt (8.42), completion percent (66.1%), and, with 25 touchdown passes and only 7 interceptions, his TD to INT ratio, 3.57:1, was more than twice his previous best (1.69:1 in 2012).

Apart from the obvious reasons that ring true for just about every young quarterback (maturity, experience and continuing with the same offensive system), what changed for Dalton? Here are the top five reasons I think the fifth year quarterback had a career year:

1. The health of Tyler Eifert and Marvin Jones

With almost an entire year to recover from an elbow injury suffered in Week 1 of 2014 coupled with the departure of Jermaine Gresham, the stage was set for Eifert to show fans why the Bengals selected him in the first round of the 2013 draft. And boy did he deliver. Eifert finished the season with 13 receiving touchdowns, despite only appearing in 13 games (including a Week 14 appearance in which he left after the first drive with a concussion after an illegal hit by Steelers safety Mike Mitchell).

And Jones, who missed the entire 2014 season with ankle and foot injuries, reminded us that he can be a huge playmaker and fantastic complement to A.J. Green. He was second only to the five-time Pro Bowler in both receptions (65) and receiving yards (816).

It should also be added that Green missed parts of five games in 2014, only playing 666 snaps after playing 1,078 in 2013. In 2015, Green played in every game.

2. Tom House's impact

Back in April, Dalton was eager to show Bengals fans the improvement he had made thanks to the time he put in with House and his staff in California at USC. Dalton said House's tutelage helped him with his arm strength and putting spin on the ball. At the time, some may have thought this was exaggerated offseason talk. But Bengals fans saw that wasn't the case once the regular season rolled around.

Dalton did not get complacent after a hot start to the season. Rather, in October, Dalton checked in with one of House's coaches, Adam Dedeaux, during the bye week to make sure his mechanics were still on-track (they were). Dalton actually was in touch with House or his staff on the phone after every game of the season.

3. Hue Jackson dug deep and pulled out a leader

Jackson repeatedly mentioned that he wanted Dalton to be more assertive. And Cincinnati's former offensive coordinator arguably found a great source of motivation in July. Jackson believes that Dalton took an embarrassing display of immaturity (I'll just refer to it as "The Softball Slight") and used it as fuel. Sure, Dalton is a great person and a hard worker, so it might be hard to believe he would improve just to spite some disrespectful fans. But he's also a competitor. One would think taking a franchise from the lowest of lows in 2011 to a model of consistency would be appreciated. When it wasn't (by what was only a small fraction of Bengals fans), Dalton decided to remind us just how valuable he is.

4. Struggles in the running game

For years, we've heard that Marvin Lewis wants to win with defense and a strong running game. Unfortunately, it seems those two haven't happened at the same time. This year, the Bengals finished 23rd in yards per rush attempt. Every week was supposed to be Jeremy Hill's breakout game. It never happened. So Dalton had to shoulder more of the burden. As a result, the Bengals scored more points per game during the 2015 season (26.2) than they did in 2014 (22.8) and Dalton was better prepared to carry the team when needed. It was his passing that brought the Bengals back in clutch wins over the Baltimore Ravens in Week 3 (video highlights and analysis), the Seattle Seahawks in Week 5 (video) and the Pittsburgh Steelers in Week 8 (video). Don't get me wrong-- if Hill can get back on track, it will be huge for the success of the offense next year. But forcing Dalton into more of a leadership role did a lot of good for his overall development.

5. The return of the pass rush

In 2013, Dalton threw 33 touchdowns and 20 interceptions on 7.33 yards per attempt. In 2014, those numbers dropped to 19, 17 and 7.06. Why the disparity? A major reason Dalton was able to take so many chances two years ago was that he knew he had the backing of Cincinnati's big-play defense (43 sacks in 2013). Meanwhile, in 2014, the pass rush was seemingly non-existent, as Cincinnati finished dead last in the league in sacks with 20. In 2015, a fully recovered Geno Atkins (11 sacks) teamed up with Carlos Dunlap (13.5 sacks) to ravage opposing offensive lines, and the Bengals as a team finished with 42 sacks. Also, after allowing the fifth fewest points in the league in 2013 (19.1), Cincinnati dropped to 22nd (21.5) in 2014, before rising again in 2015, finishing second in points allowed (17.4). In other words, Dalton (who averaged a career high 8.42 yards per attempt in 2015) was no longer forced to play the time of possession game-- he was free to throw. Only this time, Dalton's maturity and improved mechanics translated to greater efficiency than he displayed in 2013.

What does all this mean for 2016?

If Cincinnati can lock up Jones, Dalton will once again get to work with two superb deep threats and a rising star at tight end. Retaining Mohamed Sanu would be an added bonus, as he is a tough receiver who made some clutch catches during the course of the Bengals' 12-4 season. With all or some of those guys returning, Dalton should be able to sustain an excellent touchdown-to-interception ratio.

The progress Dalton made in terms of confidence and leadership is not likely to vanish with the defection of Jackson to the Cleveland Browns. In fact, the promotion of former quarterbacks coach Ken Zampese to offensive coordinator likely means Dalton is being entrusted with even more responsibility and decisions in the game. In 2015, Dalton made astute adjustments at the line of scrimmage that resulted in huge plays (like this great run by Bernard). With even more opportunities to run plays with which he is comfortable in 2016, expect Dalton to continue his upward trajectory and for the running game to get back on track.

Of course, Dalton's season did end on a sour note: a redzone interception on a screen pass to Giovani Bernard against the Steelers caused Dalton to fracture his right thumb. But one thing he showed us is that he's very good at learning from his mistakes. Just as he stopped throwing into traffic to Green in 2015, Dalton will likely improve his timing on short passes next season. The game will only continue to slow down for the 28-year-old signal caller. And that means plenty more years of success in Cincinnati.