# Fantasy, in Theory: Newton's Laws, (and I Don't Mean Cam)

430 years ago, Sir Isaac Newton published his Philosophiæ Naturalis Principia Mathematica and gave us a template to dominate our fantasy leagues.

1. An object at rest will remain at rest until some force acts upon it. An object in motion will remain in motion until some force acts upon.
2. Force equals mass times acceleration
3. For every action, there is an equal but opposite reaction.

This is Fantasy Football, in Theory, a column devoted to fantasy strategy in the abstract. While most fantasy articles are loaded with specific advice— add him, trade for him, start him— you'll find that largely absent here.

Instead, the focus is less on short-term gains than on long-term ones. By incrementally improving the way we think about fantasy football, we can create small advantages that will pay dividends for years to come.

Many of you doubtless recognized the rules at the top as Isaac Newton's three laws of motion. When Newton wrote Philosophiæ Naturalis Principia Mathematica and first laid out his laws, he intended to explain the motion of the planets in the heavens.

My goals here are less lofty. I just want to explain the motion of the players in your leagues. Thankfully, they're still up to the task.

# Newton's 1st Law

• An object at rest will remain at rest until some force acts upon it. An object in motion will remain in motion until some force acts upon it.

With Newton's first law, he introduced us to the principle of inertia. Inertia is an object's basic resistance to any changes in motion.

Anything with mass has inertia, but I find that quite a few things without mass seem to possess it as well. Once player values are set, those values tend to remain static until a large outside force acts upon them.

Andrew Luck provided an excellent example of this phenomenon this last offseason. In May and June, Luck was drafted, on average, as a top-4 fantasy quarterback. Once his value was set, Luck tended to remain there until a news story broke and pushed his value down.

But once Luck's value started falling, it tended to continue trending downward. On August 14th, Colts owner Jim Irsay raised the possibility of Luck missing the regular-season opener. In the week immediately following, Luck's average draft position dropped to the 7th quarterback off the board.

But, even absent further news developments, Luck's value continued to fall from there. From August 15th through season kickoff, the only significant developments on Luck were that the Colts activated him from the PUP list and confirmed that he would miss the regular-season opener.

Those developments should have largely offset, but they didn't. Instead, Luck's average draft position fell all the way to QB13. Once his value was in motion, it tended to remain in motion.

Why do risers continue to rise and fallers continue to fall even after the new developments stop rolling in? A lot of it has to do with how drafts operate, with participants gauging value in relation to average draft position.

If an owner likes a particular sleeper and wants to make sure he is rostered, that owner will likely to commit to drafting that sleeper a round or two above his ADP. This raises the player's ADP for the next week by a round, so another owner who likes him as a sleeper will have to draft a round earlier, still.

A similar effect is in play with fallers. An owner who ordinarily wouldn't want a player might become inclined to take that player if he falls a round or two below his ADP. Owners drafting fallers a round or two past ADP likewise causes ADP to drop a round or two at a time.

The net result is not a sudden course correction, but rather a steady increase in ADP until the value is gone.

# Newton's 2nd Law

• Force equals mass times acceleration

So we know player values tend to remain still until a new development disturbs their equilibrium. Newton's second law explains what happens when that disturbance occurs.

For physical objects, Newton's second law describes the relationship between how much mass they have, how much force is applied, and how fast they move. To accelerate a very large object very slowly, a certain amount of force is required. Applied on a very small object, that same force will produce a lot of acceleration.

Player rankings in fantasy football behave similarly. They may lack physical mass, but our level of certainty imparts a certain mental mass to their position.

The kickoff game between New England and Kansas City is illustrative of this point. Tom Brady and Alex Smith are both long-time veterans with more than a decade of starting experience. Our opinions of them are pretty firmly fixed.

As a result, Tom Brady can have a bad (by his standards) game with a sub-50% completion percentage and zero touchdowns, and for the most part, we aren't changing our opinion of him as a top fantasy quarterback.

Meanwhile, Alex Smith can pass for nearly 400 yards and 4 touchdowns and we aren't suddenly considering him an elite fantasy option. Against that one monster fantasy game, we weigh the fact that in his 4 years as a starter in Kansas City, he averages just 20 passing touchdowns per 16 games.

To be sure, their performance in week one produced force and that force moved our opinions of Tom Brady and Alex Smith. It just didn't move them much.

Now imagine that instead of Kansas City, New England had been playing Tampa Bay. Imagine that it was Jameis Winston who had 368 passing yards and 4 touchdowns in prime time.

Winston has only been in the league for two years and is clearly still developing as a player. We are far less certain about exactly who he is than we are with Alex Smith, which means there's less “mass” to his ranking. As a result, the exact same amount of force would produce much more movement in opinion.

# Newton's 3rd Law

• For every action, there is an equal and opposite reaction

Phrased slightly differently for a fantasy crowd, Newton's 3rd Law could translate to “for every riser, there must be a faller”. The corollary would be “everyone can't be sleepers”.

Rankings are a zero-sum game. Owners can only have three top-3 quarterbacks at any given moment. If a new quarterback joins that trio, an old quarterback must be displaced. If a receiver rises 20 spots in the rankings, all the other receivers must collectively account for a 20-spot drop, (whether it's one receiver dropping 20 spots, or 20 receivers dropping one spot each).

Attention gets focused on players who fall due to injury or poor performance, but at the same time, there are dozens of players who are playing pretty much as expected yet still seeing their value fall as hot sleepers start passing them.

Consider, for instance, Tyrell Williams. Williams was drafted as the 40th receiver in drafts this offseason, on average. Through two games, he's performed pretty much as expected. In his surprise breakout campaign in 2016, he averaged 4.3 receptions and 66.2 yards. Through two games in 2017, he averages 4.5 receptions and 54 yards.

Williams topped 50 yards in both games and demonstrated that he still has a role on the Chargers despite Keenan Allen's return. Still, at any given moment, there's only so much mind space to devote to wide receivers, and trendy early-season stars like J.J. Nelson and Kenny Golladay are dominating it.

Williams was drafted six or more rounds ahead of that pair, and still ranks higher than them in Bob Henry's rest-of-season projections, but simply because he's not been rising, he's found himself falling in many fantasy leagues.

# Managing your team like Sir Isaac

Okay, so Newton's laws can be used to describe player movement in fantasy football. That's an interesting observation, but what can we do with it?

As I said at the top, the goal of Fantasy, in Theory is less giving specific, actionable advice than changing the way we think about fantasy, (though if you really want actionable advice: maybe see what Tyrell Williams is going for in your leagues). Here are a couple of ways thinking about player movement in terms of Newton's laws can help you accumulate value.

Newton's First Law: most useful around draft time, the key takeaway here is, outside of dramatic situations like suspensions and season-ending injuries, ADP updates incrementally in response to new developments instead of all at once.

If a player draws rave reviews during training camp, don't assume that just because his value has risen it means his value has topped out. Usually, it will continue to rise for a little bit afterward. If a player has a monster preseason game, his ADP might still be rising two preseason games later.

Similarly, if a player starts cold or sees a bit of negative news, don't assume that just because the bottom didn't drop out all at once, it's not going to keep going down.

And if the bottom does drop out suddenly on a player's value, often times it's worth buying cheaply as the realization that the initial reaction was an overreaction can send it slowly creeping back up again over the coming weeks and months.

Newton's Second Law: inertia is a tremendously important concept in fantasy football, both in constructing your roster and in executing trades. If you've been playing in a league with the same owners for a while, you can usually get a feel for which of them have lower levels of inertia on their mental rankings and which have higher.

If an owner in your league is always trying to trade for whoever had a big game or sell whoever had a bad one, that owner has very low inertia. If an owner is still clutching highly-drafted disappointments in a death grip after week 8, he or she has very high inertia.

Knowing which type of owner is which is very helpful when you want to sell high on a player on a hot streak or sell low on a player on a cold streak.

Additionally, in deeper leagues where you have enough bench spots to afford you the luxury of fliers, you should make efforts to populate the bottom of your roster with players with a low amount of inertia.

Essentially, if everyone performs to expectations, end-of-roster guys are useless. At that point, a player needs to rise in our estimation to be worthwhile, so it makes sense to focus on players for whom the least force will produce the greatest rise.

Again, the point is less about specifics, but an example of a player right now with low inertia would be running back Matt Jones. Matt Jones is probably useless, (from a fantasy persective, anyway— I'm sure he's a perfectly nice guy in real life). he was cut by Washington this offseason, went unclaimed, and has been hanging around on Indianapolis' practice squad. The Colts just recently elevated him to the active roster.

A roster spot spent on Matt Jones will probably not return any value. But that's true of any end-of-bench stash in a deep league. Jones is still an interesting flier, however, because of how little it would really take to elevate him in the rankings.

The two running backs ahead of him on the depth chart are old, (34-year-old Frank Gore), and unproven, (4th-round rookie Marlon Mack, who has 21 rushing yards on 16 attempts). A 12-carry, 72-yard game by Jones on Sunday might be enough to vault him into consideration as a flex starter. Which, with your 20th roster spot, is about the best you can hope for.

Newton's Third Law: While everyone focuses on players who are rising and falling due to developing news, the players who are getting displaced fall through the cracks. Often players find themselves rising and falling, not through their own merit, but rather by default.

By paying attention to these players while everyone else's attention is focused elsewhere, you can tap into a market with far less price competition and often walk away with much better value.

Obviously, none of this provides The One Secret Move To Dominate Your League. Changing the way you think about fantasy results in less obvious gains, but multiplied over a long enough timeframe, the end results can still be the same.