It's third-quarter distribution time, and investors' news feeds are clogged with press releases from master limited partnerships spreading the word on their payouts. Today we're taking a look at the biggest distribution pops on a year-over-year basis.

The top 5
The following five master limited partnerships have posted the largest year-over-year increase to their distributions for the third quarter, as of this writing.

MLP

Dist.

Annualized

YOY

QOQ

Consecutive Increases

PetroLogistics (NYSE: PDH)

$0.45

$1.80

114%

50%

1

Atlas Energy (ATLS)

$0.46

$1.84

70%

5%

5

Atlas Resource Partners (NYSE: ARP)

$0.56

$2.24

30%

4%

6

EQT Midstream Partners (EQM)

$0.43

$1.72

23%

8%

3

Sunoco Logistics Partners (NYSE: SXL)

$0.63

$2.52

22%

5%

34

Source: Company releases.

At first glance, you might think PetroLogistics investors would be jumping with joy about a 114% increase. But another look at the "Consecutive Increases" column belies another story altogether. PetroLogistics is a variable-rate MLP, which means you never know whether the distribution is coming or going. Sometimes, as is true this quarter, the distribution is huge, and then sometimes, as was true in the third quarter of 2012, it's not.

You'll find more than a handful of question marks over at Atlas Energy and Atlas Resource Partners, where investors are forced to reconcile excellent operational results and distribution increases with, among other things, low natural gas prices, and other events out of the partnership's control that caused management to re-evaluate its distribution guidance for the rest of this year and next. At this point, it looks virtually impossible for Atlas Resource Partners to hit the $2.35 annualized distribution it reaffirmed in May.

On the flip side, you have two well-run midstream MLPs that are converting reliable income into reliable distributions for investors. EQT Midstream Partners is a relatively new MLP, derived from the midstream assets of EQT, an exploration and production company based primarily in the Marcellus Shale. EQT Midstream's management forecast $0.03 distribution increases every quarter in 2014, without dropdowns from the parent company, so this new MLP is certainly off to a great start.

Ultimately, Sunoco Logistics really looks like the best opportunity here, with terrific year-over-year distribution growth paired with an outstanding distribution history of 34 consecutive quarterly increases. Keep in mind that its parent company, Sunoco, exited the refining business last year, yet SXL continues to grow. If you weren't taking refining midstream logistics spinoffs seriously before, Sunoco Logistics presents one very good reason to do so now.

Bottom line
There is always more to distribution increases than meets the eye. Often, the best MLP investments float below the headlines, offering up sustainable increases quarter after quarter, while the headline hogs are one-and-done pops that don't always make for reliable long-term investments.