The 2016 NHL Draft is now just four days away. In less than one week, the Philadelphia Flyers will infuse their prospect pool with a fresh wave of talent, taking full advantage of at least ten picks in the upcoming draft.

Even though the draft will last through Saturday, their most important selection will come on Friday night. Due to their late-season charge to the playoffs and subsequent first round exit, the Flyers are locked in at pick #18 in the first round. Last year, it became clear in the days leading up to the draft that defenseman Ivan Provorov was the team's top target at pick No. 7, and the road map to adding Provorov was fairly straightforward, considering the high pick that Philadelphia possessed.

This season, the scenarios are far more hazy. The draft could move in a number of unexpected directions while the Flyers wait for their turn at No. 18, so it's difficult to make predictions regarding the team's likely choices. Still, there are a number of tools that can help us to gain a basic understanding of how the draft might progress.

One such tool is the NHL Draft Probability Tool, created by DTMAboutHeart at Hockey-Graphs. It uses a combination of statistical concepts and mock drafts/prospect rankings from plugged-in writers like Bob McKenzie and Craig Button to estimate the odds of a player being available at a specific pick slot, primarily focusing on the first round.

Perhaps the most useful aspect of the tool from a Flyers standpoint is that it allows us to group prospects in separate tiers, based upon the likelihood of availability at pick No. 18. This makes it easy to tell when a certain player is slipping on draft day, or if a team "reached" for a player projected to still be available far later in the draft.

For Philadelphia, there seem to be five distinct tiers of prospects likely to be taken in the first round. Let's start from the top.

Tier 1: No chance to be available.

Auston Matthews (0.0% chance to be available at pick No. 18), Patrick Laine (0.0%), Jesse Puljujarvi (0.0%), Matthew Tkachuk (0.0%), Pierre-Luc Dubois (0.0%), Olli Juolevi (0.5%), Alexander Nylander (0.8%)

This is the absolute high end of the draft. Matthews, Laine and Pujujarvi are basically locks to be the top three picks, while Tkachuk, Dubois, Juolevi and Nylander will almost certainly not fall out of the top-ten.

If you're a Flyers fan with dreams of your team acquiring any of these guys, you should either pray that Ron Hextall is looking to trade up, or quickly readjust your expectations for Friday night. These guys aren't slipping to No. 18.

Tier 2: Well, you can dream.

Mikhail Sergachev (1.4% chance to be available at No. 18), Logan Brown (1.7%), Jakob Chychrun (3.3%), Clayton Keller (4.2%), Tyson Jost (6.9%)

It's unlikely that any of these five prospects will slide down to the Flyers' selection, but it's at least possible to envision scenarios in which they start to fall.

Sergachev has been unable to separate himself from the other defense prospects in the draft, despite an elite combination of size and production. Center Logan Brown has surged up mock drafts in recent months, but maybe NHL scouts aren't quite as excited about him. Jakob Chychrun's stock has steadily fallen throughout the year, as he was once viewed as a lock for the top-five. Keller is ultra-skilled but comes with some concerns about his slight frame, and quality of competition is a legitimate worry for the BCHL-stalwart Tyson Jost.

While it's tough to imagine anyone in this tier dropping all the way down to No. 18, there's a much better chance that one or more could fall into the teens as a few teams in the top-ten choose to reach for other players. If that occurs, maybe the Flyers look to trade up for a forward like Keller or Jost. With two second round picks and two third rounders as well, Hextall would certainly have the ammunition.

Tier 3: They might actually slip.

Jake Bean (14.6% chance to be available at pick No. 18), Michael McLeod (24.1%), Charlie McAvoy (29.2%)

After Tyson Jost, there is a sizable dropoff in percentages to the next set of prospects. If the probabilities hold true, these are the players who will likely be selected in the early teens.

Bean racked up the points from the back end for the Calgary Hitmen, helped by partner-in-crime (and Flyers prospect) Travis Sanheim. Michael McLeod might be the fastest skater in the draft and isn't lacking for size, either. McAvoy posted solid point totals as a freshman at Boston University, one of college hockey's premier programs.

All three prospects could end up mixed in with Tier 2 on draft day, as they certainly have the talent. But unlike the players in Tier 2, Bean, McLeod and McAvoy also have legitimate potential to fall into the late teens or early twenties. Maybe a team in the top-ten thinks McLeod is the next Ryan Kesler or Matt Duchene, or maybe too many teams come away unimpressed with his offensive production in juniors and view him as a larger Darren Helm.

By the same token, it's not impossible to envision a team ranking the high-scoring Bean or the impressive freshman McAvoy over a player like Chychrun, whose stock has progressively fallen. Nor is it difficult to imagine teams in need of defense (like Boston) preferring the calmer and more defensively-sound Dante Fabbro over Bean and McAvoy.

It's not a good idea to count on it, but one of Bean, McLeod or McAvoy absolutely could be available for the Flyers on Friday night.

Tier 4: The realistic options.

Kieffer Bellows (55.0% chance to be available at pick No. 18), Luke Kunin (61.1%), Dante Fabbro (70.1%), German Rubtsov (74.1%), Max Jones (77.4%), Julien Gauthier (82.1%)

There's a reason why most mock drafts have Philadelphia selecting one of these six players. They provide the best combination of of high-upside skillsets with a decent likelihood they will be available when the Flyers are on the clock at pick No. 18.

Bellows would be a logical choice for the Flyers, considering his size and shoot-first mentality -- two traits the Flyers could certainly use in their prospect pool. But the chances that he will be available at #18 are only a bit better than a coin flip. According to CSNPhilly, Philadelphia interviewed Luke Kunin at the scouting combine, just as they did German Rubtsov. Both would add two-way skill at the center position.

Max Jones and Julien Gauthier join Bellows as powerful scoring wingers with size. Gauthier was an elite goal scorer in the QMJHL, but questions regarding his hockey sense and playmaking ability have resulted in a decreased draft stock. Jones brings a bit more quickness to the table than Gauthier, but he also exhibited a propensity for questionable hits in juniors, calling into question his on-ice discipline.

Fabbro is the sole defenseman in this tier. But even with the Flyers currently flush with high-end blueline prospects, Fabbro could still prove to be a stylistic fit. He's a right-handed shot (only Philippe Myers among "blue-chip" defensemen in the Flyers system shoots right) and has been lauded for his preternatural calm in the defensive zone. Hextall could see Fabbro as the ideal future partner for offensive-minded lefthanded shooting defensemen like Shayne Gostisbehere or Travis Sanheim.

The best bet is that Philadelphia's first round selection will come from this tier, and luckily for the Flyers, it's filled with great options.

Tier 5: The reaches.

Brett Howden (93.8% chance to be available at pick No. 18), Riley Tufte (93.8%), Logan Stanley (97.1%), Alex DeBrincat (97.8%), Boris Katchouk (99.1%), Dennis Cholowski (99.2%), Vitali Abramov (99.7%), Tage Thompson (99.7%), Pascal Laberge (99.7%), Rasmus Asplund (99.8%)

It's not a foregone conclusion that the Flyers will take the "best player available" according to scouts and analysts not employed by NHL teams. After all, Philadelphia has its own scouting network, and looking at mock drafts only helps to get a glimpse of the industry consensus, not a bird's eye view of which specific players each team is targeting.

To be sure, there are some very intriguing talents in this tier. Alex DeBrincat has lit up the scoresheets in his two seasons with the Erie Otters of the OHL. Vitali Abramov is the QMJHL's version of DeBrincat -- ultra-skilled, but lacking in the size department. Sweden's Rasmus Asplund falls into this category as well.

Riley Tufte and Tage Thompson are on the opposite end of the spectrum, as both bring size and physicality but questions exist regarding their respective offensive upsides. There's also the next tier of defensemen (Dennis Cholowski, Logan Stanley) and a group of forwards respected more for strong two-way play than elite offensive upside (Brett Howden, Boris Katchouk, Pascal Laberge).

Any of these players could prove to be strong selections, but it's fair to note that in most rankings, they've settled mostly in the 20-30 pick range. Expect them to be more likely targets if the Flyers trade down to accumulate more picks, or use their two second round picks to move back up into the late first.