lunes, 29 de diciembre de 2014

Dive or run through the first base. What is faster?

Lately we have seen the proliferation of the concept: “It is faster to go on running through first base”.  Furthermore, in recent tv transmission during World Series between Kansas City and  San Francisco, we heard known voices, like Ozzie Guillen’s, defending this theory.

It is a reality that a great number of instructors and technical personnel of all the baseball categories also agree with this theory.  Many of them previously refused this technique because of the high risk of injury that exists when runners go head first diving into first base.  Nowadays it is argued that it is dangerous and also useless, due that, according to what they say, it is slower than continuing to run through the first base.
This position will have to obey to a reasoning and analysis that we do not know.
The most eminent defense that we have found of this theory belongs to ESPN in its Program Sport Science. Next, the video for your enjoyment:

In spite of the wide publication and support of this theory in the professional level, we see like many players seemed to have, consciously or unconsciously, a difference of opinion with instructors, coaches and technicians, since, they keep on head first diving into first base in an instinctive attempt for coming safe in pressing plays.

The “opinion” of the players comes only from what their experienced instinct tells them.  Defending players respond to that instinct that tells them when they must dive to make a wild catch over a fly ball that seems impossible to catch. 
By the way, most outfielders dive to capture distant balls because they know that if they continue to run they would not get them. This is a clearly visible reality and there should be no question about it.  Sometimes, when outfielders don´t dive in those situations most people, fans and TV commentators, agree that if they would have dived they would have made the catch. So, to dive is definitely faster than continue to run.  Now, why not when running from home to first base?.
That valuable and well paid instinct, is the same that tells runners that the only way to reach first base safe in certain critical rushing plays is head first diving.
In contrast to the wing that defends the efficiency of continuing to run  over head first dive, the players may not have a way to explain why they believe, feel or know by intuition that in certain plays it is quicker to head first dive in order to complete the plays successfully.   The declarations of Brett Gardner are an example of this after the first game of the 2010 ALCS, where, in the eighth inning, with a head first dive into first base, he was credited with an infield hit that initiated a five runs rally to take the lead in the scoreboard:

About this point we have a scientific study realized by the sports laboratory of ESPN in his program Sport Science in favor of continuing to run through first base vs the instinctive presumption of the players who believe it is quicker to head first dive into first base.

But we still have not answered the question: what is faster? Who is right?: which theory is correct?

Trusting in our own instincts and convinced by our technical knowledge, we can affirm that, with the execution of a correct technique, it is quicker to head first dive into first base than continue to run through it.
We support our positon with the following exposition:
Head first dive does not consist only of the jump and the slide, as it might be thought. The correct technique of head first dive initiates 2 steps before the jump.
These two steps of run are needed to lower the centre of gravity. This is achieved by inclining the trunk forward to realize the transition from the body vertical position up to the horizontal plane, unbalancing the body and making use of the gravity to increase the speed in 0.8 m/s (approximately) for the moment of the jump.
With the correct execution of the previous movement, in addition to increasing the speed, the propulsion of the jump is optimized to achieve the maximum extension of the body in the flight and then make use of the gravity force to go on gaining speed in the diagonal displacement.

The technique can be split into three stages:
  • Getting ready for the jump.
  • The flight
  • Landing and sliding
The first two stages are of acceleration and the third one is of brake.

PREPARATION OF THE JUMP: in this stage there is realized the transition from the vertical position of the body to the horizontal plane, lowering the center of gravity with the inclination of the trunk forward, managing to unbalance the body and making use of the gravity force to increase the length of the step and with it to get something of extra speed.

The optimum performance of this phase is made in two steps. The profit is about 0,1 m.

THE FLIGHT:  The unbalance that is found by the sudden and violent body inclination in the previous stage adds power to the concentric contraction of the  muscles involved  in the pushing of the last step and prepares a forceful muscular explosion that drives to execute a powerful propulsion jump together with the total extension of the body.

As soon as the foot leaves the ground, the body is projected in flight with more speed than the career due to the horizontal acceleration produced by the violent inclination of the body and the strong propulsion of the legs in the jump. At the same time, the gravity continues its positive contribution in the equation working its vertical acceleration of 9.8 m/s2, producing speed increases during the entire diagonal trajectory towards the base up to touching the ground.
With our studies of laboratory we have verified that the resistance of the air in fact acts as soon the foot leaves the ground, but it offers only a speed reduction of 5 % average for every linear meter, but it is completely insufficient to neutralize the potency of any of these two accelerations: horizontal by jumping and gravity (gliding) and vertical by gravity force, neither the vantage of the extent the body has beeing horizontal.
During the flight we register the bigger vantage against the runner. The flight length is about 4 meters (from feet departure to hands at the moment of body landing) and take advantage of the run by 0,81 meters (2 and a half feet).

With this explanation we hope to have clarified the confusion that has arisen on having said that speed gets lost (as much as to lose the advantage against running through the base) from the moment that the foot leaves the ground.

LANDING AND SLIDING: An optimum landing happens at the moment that the trunk and thighs make contact with the ground simultaneously. There exists a previous contact with the hands due to the position acquired in the flight that slows down the fall of the low extremities.

The friction generated by hands, trunk and legs during the slide, as we have calculated,  generates a speed decrease, after the first 0,55 m (two feet) of sliding, in an approximate value of -3 m/s for every 0,6 m of slide, which increases a little bit when applying force with the hands towards the ground.

Before touching the base, the maximum distance of optimum sliding is 0,6 m. In this way it is taken advantage of the maximum the increase of the speed acquired in the fall due to the intervention of the gravity force.

The average speed reached in the lasts 4,6 meters (flight + 0,6 m. of sliding) is 10,2 m/s vs. 8,9 m/s if continue running through the base. Its represents a vantage of 0,55 meters. This 2 feet of sliding are enough to give chance to the hand, put the fingers out of risk, rising them up. 

You can notice how by friction, after 2 feet of slide, it lose almost a feet of vantage against the runner. It goes from 0,81 meters at the moment of landing to 0,55 meters after 2 feet of sliding.

So, the sliding option lose the advantage after 4 feet of sliding. It is a considerable difference in respect to the traditional believe.

I could say: the optimum distance of sliding is 2 feet. Those 2 feet of slide let take great advantage on a safety way.

Now let's see the practical demonstration and the comparison with a continuous run through the base: 
After this detailed explanation we hope to have contributed in clarifying the myth of the theory that affirms, in a widespread way, that it is slower to head first dive into the first base than continue to run through it. 

  • All these data can be calculated with majors speeds (running and diving), like the reached by players like Bret Gardner, Jhonathan Villar, Gregor Blanco, etc. and get proportional results. 
  • In the study realized by Sport Science that shows how to head first dive into first base is slower than continue to run, they committed two errors, which we considered to be involuntary, but keys that they altered the results.

                    These two errors are:

o   Not to have considered the speed reached at the moment of the jump. For a correct comparison, it was necessary that both careers were provided with the same speed.

o    The youngster does not make use of the accumulated energy. It wastes the powerful muscular contraction obtained in the last step and so not having pushed strongly, so his technique is defective.

o  This error becomes clear at the moment that the careers are overlapped. In the program they affirm that to the moment that the foot leaves the ground it is initiated a big deceleration, which is disproportionate, since the reason of this pronounced deceleration is, simply, because there is no propulsion (much less muscular explosion).
  • As we mentioned in the initial lines, Oswaldo Guillén, in the recent World Series tv transmissions, he declared in favor of this theory and inclusive, he went further, realizing a (unfortunate) comparison where he was affirming, that if head first dive was faster, we would see the track´s athletes to head first dive into the finish line in the Olympics in search of best times. 
o   Let us say: The first reason by which they don´t head first dive is that in athletics, in contrast to the baseball, nor the extremities, nor the head count at the time of stopping the chronometer. Established in the Articles 164 and 165 of the IAAF in his numerals 2: " the time will be measured up to the moment in which any part of the body (that is to say the trunk, but not the head, the neck, arms, legs, hands or feet) reaches the vertical plane of the most next border of the finish line”.

o   With this rule, an advantage given by the hands and extended arms to reach the finish line is out of effect.

o   You can see in the following photo-finish of one of the qualifying heats of the London 2010 Olympics, how the line considered to stop the time is located at level of the trunk, even when the hand, leg and foot have already passed the finish line:

o   In the following image we can see how the athletes DO make use to the maximum the gravity and the unbalance caused by the violent inclination of the trunk in order to accelerate (stage of preparation of the jump to head first dive in baseball) and in this way, to reach quicker the goal.   They do not dive and slide themselves in the floor but take advantage to the maximum the technique herein explained, which is also used in baseball.

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